It was the plane ride that launched a thousand good deeds, and one lingering controversy.

One day in June, 2005, Bill Clinton clambered aboard the private jet of Frank Giustra, the Vancouver mining financier. Mr. Clinton needed to get to Mexico City to begin a speaking tour of Latin America and oversee the work of his sprawling charitable enterprise. The two men didn’t know each other well. But Mr. Giustra happened to have a luxury MD-87 aircraft to get him there. And he was curious about the former U.S. president and his philanthropic work.

The trip and the conversation marked the beginning of a long and mutually beneficial relationship. Soon after, Mr. Giustra became one of the largest single donors to the Clinton Foundation and rallied an entire industry to raise millions of dollars for its fight against global poverty. He, in turn, gained entrée to Mr. Clinton’s inner circle – and became Corporate Canada’s most famous “Friend of Bill.”

For more than a decade, both men have burnished their reputations by travelling the globe and collaborating on big ideas in far-flung places. Mr. Giustra’s Twitter profile is a veritable photo gallery of the two men. Here they are in Peru last November, distributing household goods to women. There they are in El Salvador earlier that same year, assisting small-scale farmers. The Canadian arm of the Clinton Foundation – the brainchild of Mr. Giustra and known as the Clinton Giustra Enterprise Partnership – has poured more than $35-million (U.S.) into eradicating poverty in parts of the developing world where many of the mining companies he helped finance do business.

“We have improved the lives of hundreds of thousands of people, in Canada and around the world,” Mr. Giustra said in a written statement to The Globe and Mail. He calls such endeavours “my life’s work.”

That work has involved rallying the support of the many high-profile industry figures and associates on behalf of Bill and Hillary Clinton, making him the most prominent figure among their extensive Canadian connections.

But playing that role has also meant being dragged into what he calls a “media circus” – because when the Clintons are involved, the tale is always more complicated than simply giving away a fortune and doing good things with it.

Bill Clinton, left, and Frank Giustra, in 2007.

Neville Elder for The Globe and Mail

A series of stories in major U.S. publications raised questions about what else Mr. Giustra gets from the relationship, beyond the satisfaction of giving back. The stories revolved around uranium and oil assets acquired by companies in which Mr. Giustra was involved. In 2005, he visited Kazakhstan with Mr. Clinton and, soon after, acquired uranium interests in the former Soviet republic. In 2007, he secured the rights to operate one of Colombia’s largest oil fields.

In both instances, Mr. Clinton introduced Mr. Giustra to the president of the country before the asset sales were completed. Mr. Giustra has repeatedly denied that there was any political interference or that he donated to the charity to further his business interests. Though many have tried over the years, no one has produced evidence that it was the Clinton connection that helped to secure the deals. “Brief meet-and-greets and photo-ops with politicians and heads of state are simply that, nothing more or less, and any sophisticated deal maker will attest that it would be naive to believe that a photo-op will secure anything in a large, complex private transaction,” said David Brown, Mr. Giustra’s lawyer, in a written response to questions from The Globe.

Mr. Giustra and his various businesses have been able to weather the scrutiny. In the battleground of public opinion, however, the Clintons have been unable to shake the negative perceptions that stem from their mixing of philanthropy, for-profit business, friendships with wealthy individuals, corporate interests, foreign interests, and politics. Their success in raising astronomical sums of money from Mr. Giustra and scores of others – some $2-billion – has also given Donald Trump, the Republican nominee, one of his best lines of attack in his battle against Hillary Clinton for the White House.

By portraying her as a Washington insider who engages in “pay-to-play” schemes, whereby donors contribute money in exchange for special access and influence, he has been able to cement a public view of Ms. Clinton as a grasping, unethical politician. In September, a Washington Post-ABC News poll found that more than 70 per cent of voters – including a majority of Democrats – believe she is “too willing to bend the rules.” In the third televised debate, when moderator Chris Wallace asked Ms. Clinton if she had kept a 2009 promise to avoid even the appearance of a conflict of interest in her dealings with the foundation, Ms. Clinton stumbled: She avoided the question, but defended the foundation as a “world-renowned charity.” If she does not capture the presidency next Tuesday, her failure to counter her rival’s “Crooked Hillary” slur will be one of the root causes of her defeat.

If she hangs on to win, however – and the polls still make her the favourite – close scrutiny of the Clintons’ extensive corporate ties will continue for as long as she’s in the Oval Office. In fact, Hillary Clinton would come to power with stronger ties to the Canadian business elite than any president before her. A Globe examination of Clinton Foundation documents and Bill and Hillary Clinton’s own financial disclosures reveal a web of connections into Bay Street that runs far deeper than Frank Giustra and his immediate circle.

The list of individuals and corporations with whom the Clintons have done business in the 16 years since they left the White House is a long one. The Clinton Foundation counts some of Canada’s best-known corporations – auto parts giant Magna International Inc.; mining company Barrick Gold Corp.; and Toronto-Dominion Bank – among its large donors.

Many wealthy individuals have also supported the charity. To take three examples: Lukas Lundin, chairman of the TSX-listed mining company that bears his name, donated $1-million to $5-million. Another $500,000 to $1-million came from Toronto real estate executive Michael Cooper, whose companies own a collection of prize office properties in Canada, including 50 per cent of Toronto’s Scotia Plaza. TD deputy chairman Frank McKenna, who was Canada’s ambassador to Washington when George W. Bush was president, kicked in $100,000 to $250,000. (The disclosures come in ranges, rather than stating exactly how much an individual donated.)

Beyond the charity, the Canadian business establishment also played a not-insignificant role in the building of the Clintons’ personal fortune after Bill Clinton’s two terms as president were over.

Though Hillary Clinton was mocked for her claim that she and her husband were “dead broke” upon leaving the White House, the couple was grappling with large debts, such as millions of dollars in unpaid bills from Mr. Clinton’s endless legal fights, including his impeachment in 1998. While Ms. Clinton embarked on her own political career as a U.S. senator in 2000, her husband set about repairing their household finances and cashing in on his postpresidential life, mostly through speech making and book writing that proved extraordinarily lucrative.

Since 2001, the couple has pocketed $117.3-million in speaking fees. Most of that was earned by Bill Clinton and more than 10 per cent of it came from events in Canada, usually sponsored by big-name Canadian companies.

Skip ahead to see a full list of Bill and Hillary Clinton’s Canadian speeches – and how much they got paid

While Ms. Clinton’s opponent in the Democratic primary, Bernie Sanders, criticized her for giving high-priced speeches to major Wall Street firms such as Goldman Sachs, one of the most active financial institutions in procuring the Clintons’ services was TD Bank. Canada’s second-largest bank has sponsored a series of events featuring the Clintons as the star attraction, and from which they earned a seven-figure sum for several days’ work.

In November, 2008, Mr. Clinton earned $525,000 for three speeches in Moncton, Montreal and London, Ont. The following May, he spent two days in Canada, earning another $525,000 for speeches. All of his appearances were at motivational events organized by The Power Within Inc., which produces training programs for the general public and corporations and is sponsored by TD Bank.

Among the Canadian banks, TD has the most at stake in the U.S. market. It ranks among the top 10 retail banks in the United States, with 26,000 employees and a network of 1,300 branches along the East Coast, and it is the largest shareholder in U.S. online broker giant TD Ameritrade. A spokesperson for TD Bank said providing clients with face time and “unique opportunities to engage with diverse views and opinions from well-respected leaders” is a proven crowd pleaser.

But such events are not an effective way to lobby for specific policy changes, executives say. A former TD executive who has worked with both Clintons notes that the bank’s sponsorship of Bill Clinton’s 2008 speaking tour came after Hillary Clinton had been vanquished in the 2008 Democratic primary by Barack Obama, and it was far from clear what her political future would be. “If you’re looking for a connection between the speeches and what’s happening in this year’s election, it’s not there,” the executive said, “because we’re not that smart.”

TD has not been alone in using the Clintons as a way to gain favour with top customers or inspire employees. Canadian Imperial Bank of Commerce – whose longest-standing board member, Gordon Giffin, is a long-time ally of the Clintons who raised money for Hillary’s first presidential bid – hired the former secretary of state to make appearances following the publication of her memoir in 2014. Ms. Clinton spoke to a sold-out lunch crowd in Winnipeg on Jan. 21, 2015, and then delivered the keynote address that same evening in Saskatoon, as part of the Global Perspectives series sponsored by CIBC. She earned $470,000 for what were some of her final paid speeches before she announced her run for the presidency.

Ms. Clinton was a “huge draw” based on her global perspective, said a CIBC spokesperson. “Hiring prominent speakers is something we do regularly as a value-add for our clients.”

Agents for the Clintons typically sign up half a dozen corporate sponsors for each event. Clients pay a premium of roughly $100,000 to be the lead sponsor and in return receive an opportunity to share the stage with the Clintons. At one event in Toronto in 2009 where Mr. Clinton and Mr. Bush appeared on stage together, marking the latter’s first major public appearance since leaving the White House, Mr. McKenna, the deputy chairman of TD Bank, got to swap stories with them, resulting in the bank getting a mention in The New York Times.

Frank McKenna, left, with former U.S. presidents George W. Bush and Bill Clinton in Toronto.

Handout/TD Bank/Reuters

That profile, along with the thrill of being in close proximity to a potential future president or to Mr. Clinton and his considerable star power, is what keeps corporations lining up to hire them.

But the notion that such events offer much opportunity for backroom lobbying of a potential future president is wrong, according to bankers and executives who have been involved with them. At one speech Ms. Clinton gave in Calgary in March, 2014, about 100 people associated with sponsors TD Bank and the Calgary Chamber of Commerce milled about sipping wine and bottled water at a reception before, including Mr. McKenna. There was just enough time to shake her hand and pose for a photo, said one of the attendees. “Within the span of about three seconds, you stood there, you said: ‘Hi. How are you?’ And that was it.”

Still, the speaking events and associated fees are not without controversy. An anti-Clinton book published last year by Peter Schweizer, a Republican activist and speechwriter, attempts to draw links between Hillary Clinton’s rising influence as Secretary of State from 2009 to 2013 and Bill Clinton’s rising fees. “Most ex-presidents see the demand for their speech-making decline as they move farther away from their time in office. The opposite applies to Bill.”

On the philanthropic side, the lion’s share of the money that the Clintons have raised from their Canadian connections has come not from the Toronto banking community, but through Mr. Giustra and his associates in the resource industry.

Throughout his career, Mr. Giustra, 59, has straddled the world’s of mining and film production. He transformed Vancouver brokerage firm Yorkton Securities Inc. into a major force in the world of international mining in the 1980s. In 1996, he left Yorkton, just as the mining sector was about to crash due to the Bre-X Minerals fraud and tumbling gold prices, and founded independent film company Lions Gate Entertainment Corp.

By 2001, he was focused on mining again, convinced that gold prices were poised for a rebound. He teamed up with Ian Telfer to acquire control of Wheaton River Minerals Ltd., a dormant company valued at $20-million. Four years later, Wheaton merged with Goldcorp Inc., now Canada’s second-largest gold producer. “We both believed that the gold price was about to break out,” Mr. Telfer, chairman of Goldcorp, told The Globe. “Turned out we were right.”

The huge rally in gold and other metals prices helped make both men wealthier than they ever could have imagined during the sector’s dark times. And by the middle of the last decade, Mr. Giustra was turning more of his attention to how he could use his fortune. Around that time that he met Mr. Clinton, of whom he once said: “My money is more effective backing Clinton than any other person I can think of on this planet.”

Through his personal charitable vehicle, the Radcliffe Foundation, Mr. Giustra has donated $66.4-million (Canadian) directly to the Clinton Foundation, ranking him in the top five of all donors. He also drummed up about $20-million in donations from high rollers in the investment community at a lavish 60th birthday party in 2006 for Mr. Clinton. The star-studded bash at the Fairmont Royal York in Toronto included appearances by actor Billy Crystal and singers James Taylor and Sarah McLachlan.

Mr. Giustra did not stop there. The following year, he came up with the idea of creating the Canadian arm of the foundation, the Clinton Giustra Enterprise Partnership (Canada), through which he has contributed a further $35.4-million. Mr. Telfer has contributed $2.3-million to the partnership through his charitable vehicle, Canada Revenue Agency filings show. Mr. Telfer said that he and many others in the mining sector were already supporting philanthropic initiatives; the Clinton Foundation’s work, which takes place in some of the same developing countries in Africa or South America where miners operate, “resonated with many of us in the mining industry.”

Mr. Telfer is part of a network of loyal associates who have profited handsomely from Mr. Giustra’s various mining projects, by buying into one of his shell companies before he rolls in a new set of mining assets. Another is Neil Woodyer, himself a Clinton Foundation donor. The latest venture of the two men is a company called Leagold Mining Corp., which has raised $35-million for acquisitions. Mr. Giustra is on the board and Mr. Woodyer is the chief executive officer, currently on the hunt in Mexico for mining assets.

Mr. Woodyer also donated to the Canadian arm of the Clinton Foundation. Supporting the work of the charity, which focuses its efforts in Latin America and other parts of the developing world, was a no-brainer, he said. While mining companies are good at digging holes, he said, they are not good at the “soft relations,” including long-term social and economic initiatives. “We were not thinking in terms of Washington politics,” Mr. Woodyer said in an interview. “Our involvement has been associated with mining and supporting Frank’s work.”

No matter how pure the intentions of the donors, though, the Clintons’ decision to raise funds from wealthy foreigners has proved to be a persistent thorn in the side of Hillary Clinton in her presidential campaign. Ms. Clinton has stressed she never made decisions as a U.S. senator or secretary of state based on donations to the foundation. But the “unique complication” that the charity would pose for her was anticipated during her Senate confirmation hearings for the cabinet post in 2009. “The Clinton Foundation exists as a temptation for any foreign entity or government that believes it could curry favour through a donation,” said then-senator Richard Lugar, a Republican, in calling on the charity to ban all foreign donations.

The foundation did not do so, and Ms. Clinton has paid a political price. One e-mail chain among the tens of thousands hacked from the accounts of Ms. Clinton’s campaign chairman, and released by WikiLeaks, sheds light on the potential for conflicts between Ms. Clinton’s role as a political figure and the charity’s sweeping global activities. The King of Morocco – a country with a spotty record on human rights – agreed to host a Clinton charitable summit in May, 2015, and give $12-million (U.S.), but only if Ms. Clinton attended the event. “This was HRC’s idea,” Huma Abedin, a top aide to Ms. Clinton, says in an e-mail, referring to her boss by her initials. “She created this mess and she knows it.”

Such e-mails – which her campaign has refused to authenticate – have proved embarrassing for her, giving Mr. Trump fodder for his stump speeches and forcing the Clinton Foundation to rethink how it operates. Bill Clinton has promised to put in place new restrictions if his wife wins the election – it would no longer accept donations from foreign countries or corporations and Mr. Clinton would step down from the board.

Scott Amey, general counsel of the Project on Government Oversight, a Washington-based non-partisan watchdog, said the proposed restrictions are a good first step, but more needs to be done to address potential conflicts of interest, including disclosing any meetings between White House staff and donors to the charity. “You want to make sure that your government is above reproach and is doing things in the best interests of taxpayers, and not in the best interests of political donors or family friends,” Mr. Amey said.

For his part, Mr. Giustra has said that in the event of a Hillary Clinton victory, he would spin off the Canadian charity into an independent entity, with a new name and no ties to the Clinton Foundation. It would “bring on new partners and funders” and Mr. Clinton would no longer be invited to travel on Mr. Giustra’s private jet, according to Mr. Brown, the financier’s lawyer.

“Without exaggeration, the charity’s life-saving work is Mr. Giustra’s life’s work, is very important and will continue on, regardless of sensationalistic headlines in the media, the usual drama of any particular election cycle or the identity of its participants.”

A formal separation between the charities of Mr. Giustra and the Clintons might, in fact, simplify matters for Mr. Giustra. Even relatively small business deals have been made more complicated by his close relationship with them.

Several years ago, for instance, a small publicly-traded company that he backed, Cannon Point Resources Ltd., gave $100,000 worth of stock options to the Clinton Giustra Enterprise Partnership.

Then, last year, Cannon Point merged with Northern Dynasty Minerals Ltd., a Vancouver company that has been locked in a legal battle with the U.S. federal Environmental Protection Agency. At stake is a potential treasure buried in granite-like rocks along a remote stretch of southwestern Alaska. The property, known as Pebble, contains not only copper and silver riches but at least 70 million ounces, or $90-billion (U.S.) worth, of gold. But it’s unclear whether anyone will ever be allowed to extract it: The area is also home to the world’s largest population of sockeye salmon.

The EPA has blocked the Pebble project, citing risks to spawning grounds in a nearby watershed. Northern Dynasty has accused the agency of misconduct by vetoing the project before undertaking any scientific inquiry. The fate of the mine could be decided on the watch of the next president.

The EPA has blocked the Pebble project, citing risks to spawning grounds in a nearby watershed. Northern Dynasty has accused the agency of misconduct by vetoing the project before undertaking any scientific inquiry. The fate of the mine could be decided on the watch of the next president.

What if that president is Hillary Clinton? Would the Giustra connection help the miners? “To even suggest that our client would seek to engage in political interference or intervention in connection with a government regulated approval process is beyond reckless and absurd,” said Mr. Brown.

But Mr. Giustra is taking absolutely no chances. He has already sold most of his shares in Northern Dynasty and plans to sell the rest soon, before the next U.S. president is sworn into office in January, his lawyer said.

“Although he continues to like the asset, think highly of management and the company’s prospects,” said Mr. Brown, “our client feels his continued share ownership will be distracting to the company.”