Mikhail Prokhorov is behind a lawsuit to discredit the doctor who exposed the Russian doping scheme.

Nets owner Mikhail Prokhorov is providing financial support for a lawsuit attempting to discredit the doctor who exposed the Russian doping program, the New York Times reports.

The Russian billionaire was the head of the country’s biathlon federation during the last Olympics. Now he’s backing a lawsuit that will be filed Tuesday in New York accusing Dr. Grigory Rodchenkov of defaming three former Russian biathletes.

The suit seeks $10 million in damages for three retired Russian Olympians—Olga Zaytseva, Yana Romanova and Olga Vilukhina—who were stripped of their silver medal in the biathlon relay at the Sochi games.

“There are a number of individuals who are providing support for this challenge, both financial and otherwise,” the lawyer for the Russians, Scott Balber, told the Times. “Mr. Prohkorov is certainly one of them, but he’s not the only one.”

Rodchenkov, the former head of Moscow’s anti-doping lab, fled to the United States in 2016 and revealed that Russia had been running a massive doping operation for its Olympic athletes. The revelation led the IOC to ban more than 100 Russian athletes from the 2016 Olympics and to force Russians to compete under a neutral flag at the 2018 Olympics.

The suit is an attempt to cast doubt on Rodchenkov’s well-evidenced claims, and the Times notes that it is unlikely to succeed.

Rodchenkov previously accused Prokhorov of paying hundreds of thousands of dollars as a bribe to biathlete Irina Starykh to dissuade her from exposing the doping scheme before the Sochi Olympics. Prokhorov denies the claim.