A whistleblower who exposed doping by Russian athletes who competed in the 2014 Winter Olympics and who was hit with a libel lawsuit is punching back through the courts with claims of his own, accusing the Russian billionaire who owns the Brooklyn Nets National Basketball Association franchise of trying to silence him.

Dr. Grigory Rodchenkov—who was featured in the Oscar-winning documentary “Icarus“—ran Russia's laboratory for assuring compliance with World Anti-Doping Agency regulations. Rodchenkov said in court papers filed Monday that the lab was actually used to further a state-sponsored conspiracy to load up Russian athletes participating in the 2014 Winter Olympics games in Sochi, Russia, with performance-enhancing drugs.

Rodchenkov said he took part in the scheme by developing a steroid cocktail for athletes, as well as developing a system to swap out potentially “dirty” urine samples from athletes who used performance-enhancing drugs with samples that the same athletes provided before they used.

The alleged scheme did not come to light after the Sochi Winter Olympics, in which Russian athletes took 33 medals.

A German TV station aired a documentary alleging that Rodchenkov and others participated in a doping scandal, and Rodchenkov, who said he feared that he would be made to take the fall, fled to the United States in 2015 and uncovered the scheme in Sochi, which The New York Times first reported in 2016. Rodchenkov became the central figure in the 2017 documentary “Icarus” by Bryan Fogel, which was distributed by Netflix.

After the revelations, many of Russia's athletes were barred from taking part in this year's Winter Olympics because of the doping scandal.

In November 2017, the International Olympic Committee stripped medals from three Russian biathletes, Olga Zaytseva, Yana Romanova and Olga Vilukhina and banned them from future games because of anti-doping violations.

In February, the biathletes filed a libel suit against Rodchenkov in Manhattan Supreme Court, arguing that each is entitled to $10 million in damages.

Mikhail Prokhorov, who ran Russia's biathlon federation during the Sochi games, is helping to finance the libel suit against Rodchenkov.

But on Monday, Rodchenkov fought back, filing both a motion to dismiss the libel suit as well as a counterclaim under New York's anti-SLAPP law—designed to protect whistleblowers—alleging that Kremlin officials and Prokhorov have subjected Rodchenkov to harassment and threats of violence,

“With today's filings, the hunted becomes the hunter,” said Rodchenkov's lawyer, Jim Walden of Walden Macht & Haran. “Russia and its puppets have been persistently attacking Dr. Rodchenkov for too long, most recently with this frivolous lawsuit that parrots the Kremlin's slander.”

Rodchenkov is currently in hiding, his lawyers said during a Monday conference call with reporters, and if he is required to provide depositions in the cases he will do so remotely to keep his location secret.

Scott Balber of Herbert Smith Freehills, who represents the biathletes, did not respond to a request for comment, but told The New York Times that his clients have evidence that Rodchenkov “fabricated a lot if not all of the storyline” pertaining to the biathletes.

In addition to Walden, Rodchenkov's legal team includes Walden Macht attorney Avni Patel; and Gregory Diskant, Derek Borchardt, Elena Steiger Reich and Julia Stepanova of Patterson Belknap Webb & Tyler.

According to Sputnik News, a state-run Russian news agency, Kremlin officials have said that Rodchenkov is lying about the doping scandal and said that it would consider taking legal action on behalf of its athletes.

Last year, The Guardian reported that a Russian Olympic official said during an interview that Rodchenkov “should be shot for lying, like Stalin would have done.”