A Russian oligarch who secretly employed Donald Trump’s campaign manager, Paul Manafort, offered to testify before congressional committees investigating Russia’s meddling in the U.S. election, but only if he’s granted immunity from prosecution, The New York Times reported Friday.
Lawmakers have so far turned down the demands of aluminum billionaire Oleg Deripaska, lest an immunity deal compromise criminal investigations into whether the Trump campaign colluded with Russia to influence the election, according to the Times. Manafort is said to be a key figure in the FBI’s investigation.
Deripaska and Manafort worked together on an offshore fund in 2007 that quickly folded. But Deripaska also provided a $10 million annual contract to Manafort beginning in 2006 to promote Russian interests abroad, The Associated Press reported in March. During the time of the contract, Manafort was working as a campaign consultant to candidates in the Ukraine backed by the Kremlin.
Manafort was forced out as campaign chairman shortly after the Republican National Convention last year, when AP revealed he had helped a Ukrainian political party linked to Russia secretly funnel millions of dollars to two Washington lobbying firms from 2010 to 2014.
Last month, Manafort was to register with the U.S. Department of Justice as a foreign agent, as is required for someone on the payroll of a foreign interest.
The FBI also is reportedly investigating activities of Trump’s ousted National Security Adviser Michael Flynn, former campaign advisers Carter Page and Roger Stone, and top White House aide and Trump son-in-law Jared Kushner.
Deripaska, who has close ties to Russian President Vladimir Putin, traveled several times to the U.S. from 2011 to 2014 on a diplomatic passport, according to the Times. He was unable to obtain regular business visas for travel to the U.S. because of suspicions by American officials that he was linked to the Russian mob — which Deripaska has denied.
There was no indication that the FBI has sought to question Deripaska for its investigation, the Times reported.
This article originally appeared on HuffPost.