Senate Judiciary Committee Chairman Chuck Grassley said Wednesday he is looking into potential 'conflicts of interest' of Hillary Clinton's over a Russian uranium deal that was approved despite an ongoing FBI investigation of the company concerned.

'It turns out during the transaction, the Justice Department had an ongoing criminal investigation for bribery, extortion and money laundering into officials for the Russian company making that purchase,' Grassley said during a Capitol Hill hearing. 'While all of this was going on, the Clinton Foundation reportedly received millions of dollars from interested parties in the transaction.'

The Hill newspaper also reported that a key FBI informant, an American businessman with knowledge of the Russian nuclear industry's efforts to woo the Clintons and the Obama administration, was blocked by President Obama's Justice Department last year from telling Congress what he knew.

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Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, is trying to get to the bottom of an approved Russian uranium deal that he finds suspicious as involved parties had donated to the Clinton Foundation - though the Russian company was under a federal probe

Former President Bill Clinton was given Clinton Foundation dollars and speaking fees by parties associated with the Russian uranium deal - while his wife, then Secretary of State Hillary Clinton, had to approve of it for it to go through

In 2010, the Committee on Foreign Investment in the United States approved a deal that allowed Russia's Rosatom nuclear company to buy Canadian mining company Uranium One, which controlled about 20 percent of the U.S.'s uranium deposits, which was why the multi-agency committee was involved.

Sitting on that committee were former Attorney General Eric Holder and former Secretary of State Clinton, whose husband, ex-President Bill Clinton, had collected speaking fees and Clinton Foundation donations by parties associated with the deal.

Details about the donations were previously revealed in author Peter Schweizer's 2015 book Clinton Cash, with the New York Times investigating the deal on its own, finding dollars from interested parties had indeed flowed to the Clinton Foundation, as Secretary of State Clinton had to make her determination.

'Whether the donations played any role in the approval of the uranium deal is unknown,' the Times report said.

'But the episode underscores the special ethical challenges presented by the Clinton Foundation, headed by a former president who relied heavily on foreign cash to accumulate $250 million in assets even as his wife helped steer American foreign policy as secretary of state, presiding over decisions with the potential to benefit the foundation’s donors,' it continued.

But now there's a new layer to the story, as the Hill newspaper reported this week that the FBI had uncovered a Russian bribery plot in 2009 and 2010, before the committee green-lit the deal.

The Justice Department also waited until 2014 to bring any charges.

Grassley wants to find out why.

He told his Senate committee Wednesday, in earshot of witness Attorney General Jeff Sessions, that he had sent 10 letters out last week asking questions about who in the government knew about the FBI probe and when.

'In my letter, I asked the agencies involved in approving the transaction if they were aware of the criminal probe and the intelligence operation examining Russian activity,' Grassley explained.

The Iowa Republican also noted that 'Russians involved in the conspiracy were reportedly coordinating with high level officials, close to Vladimir Putin.

Turning his attention to Sessions, Grassley asked, 'What are you doing to find out how a Russian takeover of American uranium was allowed to occur despite criminal conduct by a Russian company that the Obama administration approved to make the purchase?'

Sessions said he heard Grassley's concerns and promised they would be reviewed.

'It wouldn't be appropriate for me to comment on any ongoing investigation,' Sessions also said.

If Sessions' Justice Department did probe the deal it would be a marked difference from how the Obama administration's Justice Department handled it, according to the lawyer representing the FBI's informant, according to the Hill.

Lawyer Victoria Toensing, who worked in the Reagan Justice Department and was the former chief counsel of the Senate Judiciary Committee, told the paper Tuesday she is working with lawmakers to push the Trump Justice Department or the FBI in freeing up her client to speak with members of Congress.

She told the Hill that her client possesses details on how Russian executives facilitated the 2010 Uranium One deal, sending millions of dollars in Russian nuclear funds to an entity that was then supporting the Clinton Foundation.

But last year, during the presidential election, he was not allowed to speak out, having signed a non-disclosure agreement at the behest of the FBI.

'There was corruption going on and it was never brought forward. And in fact, the sale of the uranium went on despite the government knowing about all of this corruption. So he's coming forward,' Toensing told the paper. 'He wants the right thing to be done, but he cannot do it unless he is released from the NDA.'