WASHINGTON (AP) — Russian oligarch Oleg Deripaska filed a lawsuit Friday against the U.S. Treasury Department, saying the sanctions against him have caused a "wholesale devastation" of his wealth and reputation.

The billionaire argues he was unfairly and illegally targeted by the U.S. government when he was slapped with sanctions last April targeting tycoons with close ties to the Kremlin.

Deripaska's net worth has dropped by $7.5 billion and he has watched his businesses "edge to the brink of collapse," according to the lawsuit, which was filed in federal court in Washington. The suit says it's an 81 percent decrease in his net worth.

He wants the sanctions lifted and for a federal judge to order the Treasury Department to remove him from a list of oligarchs.

A Treasury Department spokesman referred questions about the lawsuit to the Justice Department, which declined to comment.

Deripaska made his billions in the aluminum industry in the rags-to-riches privatization era that followed the collapse of the Soviet Union. He has close ties to President Vladimir Putin and once employed Paul Manafort, President Donald Trump's former campaign chairman, as a consultant.

Manafort offered to provide Deripaska with private briefings during Trump's 2016 presidential campaign, but there is no evidence such briefings ever occurred.

In January, the Treasury Department lifted sanctions on three companies connected to Deripaska, but he remained personally blacklisted.

Treasury's decision to ease the sanctions narrowly survived a Senate vote in January after lawmakers raised concerned that the Trump administration is not being tough enough on Putin and his allies.