Norwegian chess world champion Magnus Carlsen and online platform Chess.com on Friday urged a U.S. federal court to toss a $100 million libel suit brought against them by U.S. teenage grandmaster Hans Niemann, whom Carlsen has accused of cheating.

Chess.com executive Daniel Rensch and Carlsen said in their filings that Niemann is an “admitted” cheater who failed to identify any defamatory statements by them in his lawsuit in U.S. District Court in Missouri.

“After years of trying to curate a reputation as the bad boy of chess, plaintiff Hans Niemann wants to cash in by blaming others for the fallout from his own admitted misconduct,” Carlsen’s filing said.

Niemann’s lawyers did not immediately respond to requests for comment.

Niemann, 19, said in his lawsuit that the defendants are “colluding to blacklist” him from professional chess and that he has been shunned by tournament organizers since five-time world champion Carlsen, 32, accused him of cheating at the Sinquefield Cup in St Louis, Missouri in September.

Carlsen’s surprise defeat and unusual decision to immediately withdraw from the tournament set off a flurry of speculation in the chess world that Carlsen believed Niemann had cheated.

Rumor erupted into scandal later that month when Carlsen resigned after one move in a match against Niemann during an online tournament. Carlsen then released a statement saying he believed Niemann had cheated “more – and more recently – than he has publicly admitted.”

Chess.com, an internet chess server, banned Niemann after the first match against Carlsen and later published a report saying he had likely cheated more than 100 times in online games.

Niemann has admitted to cheating in online chess matches when he was 12 and 16 years old but has denied ever doing so in during tournaments involving prize money. Tournament organizers say they have not found any evidence that Niemann cheated.