WASHINGTON • In the estimation of US officials, Russian oligarch Oleg Deripaska, a man with close ties to the Kremlin, has faced credible accusations of extortion, bribery and even murder.
They also thought he might make a good source.
Between 2014 and 2016, the FBI and the Justice Department unsuccessfully tried to turn Mr Deripaska into an informant. They signalled that they might provide help with his trouble in getting visas for the United States or even explore other steps to address his legal problems.
In exchange, they were hoping for information on Russian organised crime and, later, on possible Russian aid to President Donald Trump's 2016 campaign, according to current and former officials and associates of Mr Deripaska.
In one dramatic encounter, FBI agents appeared unannounced at a home he maintains in New York and pressed him on whether Paul Manafort, a former business partner of his who went on to become chairman of Mr Trump's campaign, had served as a link between the campaign and the Kremlin.
The attempt to flip Mr Deripaska was part of a broader, clandestine US effort to gauge the possibility of gaining cooperation from a half-dozen of Russia's richest men, nearly all of whom depend on President Vladimir Putin to maintain their wealth, the officials said.
Two of the players were Mr Bruce Ohr, a Justice Department official who has recently become a target of attacks by Mr Trump, and Mr Christopher Steele, a former British spy who compiled a dossier of purported links between the Trump campaign and Russia.
Mr Steele first met Mr Ohr years earlier while still serving at Britain's MI6, where he oversaw Russia operations. After retiring, he opened a business intelligence firm, and had tracked Russian organised crime and business interests for private clients, including one of Mr Deripaska's lawyers.
To facilitate meetings, the FBI pushed the State Department to allow Mr Deripaska to travel to New York on a Russian diplomatic passport as part of a Russian government delegation to the UN General Assembly. The department had previously rejected some of his efforts to secure visas to enter the US.
According to a person familiar with the events, Mr Steele helped set up a meeting between the Russian and US officials, including Mr Ohr, during the 2015 trip.
The systematic effort to win the cooperation of the oligarchs, which has not previously been revealed, however, does not appear to have scored any successes.
The person said Mr Deripaska told the US investigators that he disagreed with their theories about Russian organised crime and Kremlin collusion in the campaign. Mr Deripaska also notified the Kremlin about the US efforts to cultivate him.