FBI agents are conducting “law enforcement activity” at the home of Russian energy tycoon Oleg Deripaska, a spokesman for the agency told NBC News on Tuesday.

Multiple agents were seen at Deripaska’s home in Washington, D.C., restricting access to the property, NBC reported.

Deripaska became widely known in the U.S. for his ties to Paul Manafort, the former Trump campaign chairman who was convicted on fraud charges stemming from former special counsel Robert Mueller’s probe of Russian interference in the 2016 presidential election.

Then-President Donald Trump pardoned Manafort in his final month in office.

In 2018, the Trump administration imposed sanctions on Deripaska and about two dozen other oligarchs and Kremlin officials with ties to Russian President Vladimir Putin’s inner circle.

Deripaska sued over the sanctions, but a U.S. judge in June dismissed his lawsuit.

The FBI and the D.C. police did not immediately respond to requests for additional information.

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