Hillary Clinton's newborn presidential campaign is reeling from new financial links between her family foundation and companies that benefited from her stewardship of the U.S. State Department.

On a day when a new Quinnipiac University poll found only 38 per cent of Americans believe she is honest and trustworthy, the leading Democratic Party candidate for president has a mess to clean up.

Part of it will involve the Bill, Hillary and Chelsea Clinton Foundation re-filing some of its annual tax returns to correct errors in how it has reported income from foreign governments.

The murky picture also includes tens of millions of dollars Bill Clinton collected in speaking fees from companies that saw their fortunes rise because of U.S. State Department actions while his wife ran the agency.

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Hillary Clinton (seen Wednesday at Georgetown University) was helping approve Russia's purchase of US uranium production as her foundation received millions from executives tied to the deal

Former president Bill Clinton (left) received $500,000 for a Moscow speaking engagement with Renaissance Capital. He also met Vladimir Putin (right), at the time Russia's prime minister, during the visit

In one case a foundation run by the chairman of Uranium One, a nuclear energy company tied to Russia, gave the Clintons' family philanthropy millions while Hillary's State Department gave its stamp of approval to the company's purchase of U.S. uranium.

The Russian state atomic agency Rosatom purchased a majority stake in the Vancouver-based company in a years-long process that unfolded from 2009 to 2013 – the same years Mrs. Clinton was America's secretary of state.

The executive, Ian Telfer, gave the Clinton Foundation $2.35 million during the same time through his family's Fernwood Foundation.

Bill Clinton, the former U.S. president, also received one of his highest speaking fees, $500,000, in June 2010 in Moscow for addressing an investment bank linked to Russian President Vladimir Putin and the Kremlin.

He earned more than $100 million for his speeches from 2001 to 2013. That number comes from financial disclosure statements filed by Hillary when she was a U.S. senator and, later, secretary of state.

Canadian businessman Ian Telfer was only shown as having donated $250,000 to the Clinton Foundation, though tax records reveal that his foundation gave millions when his company was being sold to Russia

An investigation by The New York Times uncovered the connections, based on interviews and public records in Canada, the U.S. and Russia.

Chelsea Clinton, the former first daughter whose name is now part of the Clinton Foundation's official moniker, defended the philanthropy on Thursday in New York City.

The Bill, Hillary and Chelsea Clinton Foundation does 'important' work and is 'among the most transparent' of foundations, she claimed during a panel discussion at the Council on Foreign Relations.

'What the Clinton Foundation has said is that we will be even more transparent, even though Transparency International and others have said we're among the most transparent of foundations,' Chelsea, the foundation's vice chair, said.

'I very much believe that that is the right policy. That we'll be even more transparent. That to eliminate any questions while we're in this time, we won't take new government funding, but that the work will continue as it is.'

Accepting funds from companies tied to foreign governments presents the appearance of a conflict of interest for the Clinton Foundation, since it's one avenue through which countries could try to influence Hillary and extract sweetheart deals from Washington.

The foundation is also under fire for handing the Internal Revenue Service incomplete or incorrect accounting of how much money it received from foreign governments.

Chelsea Clinton defended her family philanthropy on Thursday in New York, calling it 'among the most transparent of foundations'

Reuters reported on Thursday that the Clinton Foundation and its associated charities will re-file at least five annual tax returns to correct the mistakes.

The errors involve under-reporting, over-reporting or misclassifying millions of dollars in donations from foreign governments.

In 2010, 2011 and 2012, according to Reuters, the Clinton Foundation reported to the IRS that it received zero dollars from foreign and U.S. governments. That number stood out because it reported tens of millions in foreign government contributions in the preceding years.

PRESSURE: Likely Republican presidential candidate Carly Fiorina slammed the Clintons for 'making promises about transparency that they never intended to keep'

Foreign governments had continued to give tens of millions of dollars toward the foundation's work on climate change and economic development. The foundation listed the donors on its publicly available donor lists, but omitted them in its tax filings.

Hillary Clinton is seeing a flurry of new scrutiny applied to her years as secretary of state now that she has announced a 2016 presidential run.

Her chief female Republican rival, former Hewlett-Packard CEO Carly Fiorina, said Thursday that alleged links between the Clinton Foundation, former president Bill Clinton's speaking fees and Mrs. Clinton's leadership at State are disturbing.

'It's the Clinton way: raking in millions from foreign governments behind closed doors while making promises about transparency that they never intended to keep,' Fiorina said in a statement.

'Now they're scrambling to refile their taxes and account for her decisions as Secretary of State.'

The Russian uranium story is one piece of a larger puzzle.

When Rosatom purchased 51 per cent of Uranium One, which controls a reported one-fifth of the uranium made in the US, the reported $610 million sale needed to be approved by a committee of government agencies, including the State Department.

Committee on Foreign Investment in the United States approved the majority ownership deal in 2010.

Jose Fernandez, a former assistant secretary of state, was the principal State Department representative on the committee, and said that Clinton did not intervene with his work.

No one 'has ever produced a shred of evidence supporting the theory that Hillary Clinton ever took action as secretary of state to support the interests of donors to the Clinton Foundation,' according to foundation spokesman Brian Fallon.

The Clinton Foundation has become lucrative for one of America's most powerful political families, with Bill Clinton receiving $26 million in speaking fees from donors to the charity. Above, Clinton speaks in January

Approval of Uranium One's sale helped Russian state nuclear agency Rosatom gain control of uranium assets in the US and Kazakhstan (pictured)

He said that is was 'utterly baseless' to say that Clinton helped push the deal through while her foundation received a windfall in donations.

When Clinton joined the Obama Administration as Secretary of State, she signed an agreement saying that the Clinton Foundation would not receive money from foreign governments and disclose all donors.

However, the donations from Uranium One's Telfer reveal that it was still accepting undisclosed donations from private individuals whose businesses and interests aligned with governments such as Russia or businesses.

Sixty companies that lobbied the State Department when Hillary Clinton was Secretary donated $26 million to the foundation, at the time run by her husband, according to The Wall Street Journal.

The Clinton Foundation only reported that Telfer gave it $250,000, though tax records reviewed by The New York Times show that Telfer's Fernwood Foundation gave $1 million in 2009, $250,000 in 2010, $600,000 in 2011 and $500,000 in 2012.

Telfer said that his donations were to support his friend Frank Giustra, who has deep ties to the Clintons and once benefited from Bill's presence on a business trip to Kazakhstan.

Up to $5.6 million may have come from other individuals associated with Uranium One.

The revelations about possible connections between the Clinton Foundation and Hillary's work in the State Department come as more information has been gathered about how the charity lined the pockets of one of America's most powerful political families.

Bill Clinton has made a total of $26 million in speakers fees from donors to the Clinton Foundation, according to a report in The Washington Post.

The former president has received more than $100 million in speaking fees since leaving office, though how much of that was from organizations that also donated to his foundation has not previously been known.

Some of the biggest donors to the foundation are financial institutions Goldman Sachs, Barclays Capital, Deutsche Bank and Citigroup, which personally paid Bill Clinton $3 million in speaking fees.

Then-senator Hillary Clinton listens to a briefing from the Committee on Foreign Investment in the United States, the organization where she would later help approve Russia's purchase of US uranium assets

Bill Clinton's trip to Kazakhstan and its president Nursultan Nazarbayev (pictured) helped paved the way for a major foundation donor Frank Giustra to start a booming uranium business there

Canadian businessman Frank Giustra (right) got a sweetheart uranium mining deal from Nazarbayev in 2008 with Clinton's help, a year after launching a 'sustainable development initiative' with the Clinton Foundation; Giustra pledged $100 million and half his earnings from mining to the foundation

His June 2010 speech to leading Russian officials at an event for Renaissance Capital netted him $500,000.

Clinton met with Vladimir Putin, at the time Russia's Prime Minister, during his visit.

All of the business dealings linked to the Clinton Foundation took place during the Obama Administration's 'reset' in US relations with Russia.

Bill Clinton also engaged in activities in the post-Soviet world not directly tied to his foundation.

In 2005 he flew to Kazakhstan with a Canadian uranium mining financier Frank Giustra and met the country's despotic president Nursultan Nazarbayev.

Clinton's appearance is seen as helping Giustra secure a deal to start his UrAsia uranium company in Kazakhstan, which would later merge with Uranium One.

Giustra would donate $31.3 million to the Clinton Foundation in 2006 and helped start the Clinton Giustra Sustainable Growth Initiative.

Russia would ultimately benefit from the deal and Clinton's involvement, and was able to secure more uranium production in its own backyard when took majority control of Uranium One in 2010 and 100 per cent control in 2013.

Rosatom said that it would not export any of the uranium out of the United States, though a rancher at the nuclear material facility in Wyoming said that the uranium is often taken for processing in Canada.

News of the Clinton Foundation's ties to uranium executives comes after criticism of the Clinton's ties to additional Eastern European money, from the Ukrainian oligarch that became one of their foundation's biggest donors.

Victor Pinchuk, the fourth richest man in Ukraine, was found to have done business with Iranian government despite US sanctions against the Middle Eastern country when he sold their oil and gas pipes in 2011 and 2012, according to Newsweek.

Many of the recent revelations have come from a book called 'Clinton Cash', written by investigative journalist Peter Schweizer.

Supporters of Hillary Clinton's fledgling presidential campaign say that the book is a partisan conservative attack.

A spokesman for the campaign said that the Uranium One deal went through the normal approval process and that Schweizer's book is 'twisting previously known facts into absurd conspiracy theories.'