Paul Manafort was pressured by a former Russian spy to pay back millions of dollars he owed while he was chairing Donald Trump's 2016 presidential campaign, according to an investigation by Time Magazine.
Victor Boyarkin said he contacted Mr Manafort on behalf of Oleg Deripaska, a Russian oligarch with close ties to the Kremlin and the subject of US sanctions since earlier this year, to collect the debt.
"He owed us a lot of money," Mr Boyarkin, a former arms dealer, told Time. "And he was offering ways to pay it back."
The allegations will add to concerns that Kremlin-linked figures had leverage over Mr Manafort during a critical part of the campaign.
Mr Trump’s supporters insist there is no evidence of collusion between his aides and Russia. The president himself repeated his familiar denial on Twitter after the latest allegations were published.
“The Russian Collusion fabrication is the greatest Hoax in the history of American politics,” he wrote. “The only Russian Collusion was with Hillary and the Democrats!”
However, critics point out that connections have surfaced repeatedly as Robert Mueller continues his federal investigation into allegations Moscow attempted to influence the election outcome, and that Russia may have been seeking to capitalise on a mix of oddballs and outsiders attracted to the unorthodox Republican candidate.
Joyce Vance, a former federal prosecutor and lecturer at the University of Alabama School of Law, wrote on Twitter: “The best case for Trump is that he didn’t know Manafort was deeply in debt to and compromised by the Russians when he hired him as campaign manager. If his vetting was that deficient, it’s not in the realm of possibility for him to run the country.”
Mr Manafort is currently in jail awaiting sentencing. He pleaded guilty earlier this year to two charges of conspiracy and witness tampering. He has also admitted other financial and lobbying crimes and could yet face more charges. He declined to comment on the Time article.
Although his crimes are not related to his campaign work, Trump critics suggest that Russian operatives were able to identify and manipulate flaws.
Mr Boyarkin said it was up to him to collect the debt from Mr Manafort. “I came down on him hard,” he claimed.
He also told Time he had been approached by Mr Mueller's investigators but declined to cooperate.
“I told them to go dig a ditch,” he said.
His alleged role in trying to push Russian influence around the world was laid bare in a new list of sanctions imposed by the US Treasury Department this month.
He was described as a “former GRU [military intelligence] officer who reports directly to Deripaska and has led business negotiations on Deripaska’s behalf”. He was sanctioned for his alleged role in trying to interfere in Montenegro’s parliamentary election in 2016.
That country’s pro-Russia opposition has been accused of trying to assassinate the prime minister as part of an effort to prevent it joining Nato. Russia has denied any involvement and there is no evidence to suggest Mr Boyarkin or Mr Deripaska were involved.
However, that plot has crystallised Western fears about how Moscow is trying to manipulate foreign democracies.
Mr Manafort’s previous work for Mr Deripaska, once Russia’s richest man, is well known. The Associated Press reported last year that from 2006 the American lobbyist had a $10m contract with him to help win positive coverage for Vladimir Putin’s government around the world, although both men said it was purely for business and consulting services.
It later emerged that lawyers for the oligarch had filed a suit against Mr Manafort in the Cayman Islands alleging that he had “simply disappeared” with $19m. A second suit was filed in New York this year accusing Mr Manafort and others of taking $26m.
Mr Manafort resurfaced in April of 2016 when he joined the Trump campaign initially as an unpaid adviser before becoming chairman in June. He joined the campaign almost broke and deeply in debt to Mr Deripaska, according to Time.
At one of the crucial moments, just before Mr Trump accepted the party nomination at the Republican National Convention in Cleveland, Mr Manafort offered to brief Mr Deripaska on the 2016 race.
“If he needs private briefings we can accommodate,” he wrote in an email sent via an intermediary, his former business associate Konstantin Kilimnik, according to The Washington Post.
Mr Kilimnik referred to an associate with ties to Mr Deripaska as "our friend V", who Time says is Mr Boyarkin.
A spokesman for the Mueller investigation also declined to comment on the reports.
It leaves the Russia investigation still without a smoking gun when it comes to allegations that the Trump campaign coordinated with Moscow. However, it reinforces findings that a slew of Mr Trump’s associated were in touch with Kremlin-connected figures during 2016.