A former high-ranking FBI agent and US court interpreter have been charged with violating US sanctions by helping Russian oligarch Oleg Deripaska investigate a rival and engaging in money laundering. Charles McGonigal, who previously served as special agent in charge of counter-intelligence at the FBI’s New York office and who had probed Deripaska, and Sergey Shestakov, a Russian diplomat turned US citizen and court interpreter, were arrested on Saturday evening, the Department of Justice said on Monday. “They both previously worked with Deripaska to attempt to have his sanctions removed, and, as public servants, they should have known better,” Damian Williams, the US attorney for the Southern District of New York said.

Please use the sharing tools found via the share button at the top or side of articles. Copying articles to share with others is a breach of FT.com T&Cs and Copyright Policy. Email licensing@ft.com to buy additional rights. Subscribers may share up to 10 or 20 articles per month using the gift article service. More information can be found here.

Deripaska, who made his fortune in metals, was first sanctioned by the US in 2018, in response to Russia’s earlier annexation of Ukraine’s Crimea. McGonigal, who retired from the FBI in 2018, agreed in 2021 to “investigate a rival Russian oligarch in return for concealed payments from Deripaska”, the DoJ said. He worked for the sanctioned oligarch both via a law firm and directly, prosecutors said, and engaged in a “soup to nuts” investigation of the unnamed rival. McGonigal was paid tens of thousands of dollars for his services, they alleged. The 54-year-old McGonigal and 69-year-old Shestakov also attempted to get the sanctions against Deripaska lifted in 2019, prosecutors said. Shestakov, who was a New York-based diplomat for both Soviet and post-Soviet Russia, had remained in the US to work as a Russian interpreter in federal courts, including in the storied southern district of New York, where the case against him will be heard. If convicted, McGonigal could face a maximum of 80 years in prison, while Shestakov could face 85 years.