US chess grandmaster Hans Niemann is suing rival Magnus Carlsen for at least $100m after the Norwegian world champion accused him of cheating.
In an ongoing scandal that has rocked the chess world, Niemann is also suing website Chess.com, which published a report saying he had probably cheated in more than 100 online games.
Niemann says the defendants colluded to destroy his reputation and livelihood.
Lawyers for both Magnus Carlsen and Chess.com dismissed the allegations.
In his filing, Niemann, 19, accuses Carlsen of launching a smear campaign against him in collaboration with Carlsen’s online chess company Play Magnus, and Chess.com, which has agreed to buy Play Magnus.
He is seeking compensation “to recover from the devastating damages that defendants have inflicted upon his reputation, career, and life by egregiously defaming him and unlawfully colluding to blacklist him from the profession to which he has dedicated his life”, the lawsuit said.
A lawyer representing Carlsen said the claims are “without merit”.
“Hans Niemann has an admitted history of cheating and his lawsuit is nothing more than an attempt to deflect blame onto others,” he said.
