American grandmaster Hans Niemann, in the latest move in a scandal that has rocked the world of chess, filed a lawsuit on Thursday against Magnus Carlsen after the Norwegian world champion accused him of cheating.

Niemann, in the suit filed in federal court in Missouri, is seeking $100 million in damages from Carlsen, his company Play Magnus Group, Danny Rensch of Chess.com, the world's leading online chess platform, and American grandmaster Hikaru Nakamura.

Niemann accused the defendants of slander and libel and colluding to destroy his reputation and livelihood.

Carlsen has publicly accused Niemann of cheating, and chess.com alleged in a report earlier this month that the 19-year-old American has "probably cheated more than 100 times" in online games.

In his complaint, Niemann said the 31-year-old Carlsen, the five-time reigning world champion, Rensch and Nakamura have inflicted "devastating damages" on his reputation and career by "egregiously defaming him."

It accuses them of "unlawfully colluding to blacklist him from the profession to which he has dedicated his life."

"Since the age of 16, Niemann's sole means of supporting himself has been from the money he makes teaching chess and participating in chess tournaments," the lawsuit said.

After Niemann "soundly defeated" Carlsen at the Sinquefield Cup tournament in Missouri on September 4, the Norwegian "viciously and maliciously retaliated against Niemann by falsely accusing Niemann, without any evidence, of somehow cheating during their in-person game," it said.

Chess.com, the lawsuit said, "banned Niemann from its website and all of its future events, to lend credence to Carlsen's unsubstantiated and defamatory accusations of cheating."

The Florida-based Nakamura, an influential streaming partner of Chess.com, is accused of publishing "hours of video content amplifying and attempting to bolster Carlsen's false cheating allegations."

- 'Ready to play naked' -
Chess.com banned Niemann on September 5, shortly after the first accusations were made.

Niemann's lawsuit suggested that the move by Chess.com was made under pressure from Carlsen, whose Play Magnus company is currently being acquired for $83 million by Chess.com.

"Carlsen, having solidified his position as the 'King of Chess,' believes that when it comes to chess, he can do whatever he wants and get away with it," the complaint said.

Two weeks after his Sinquefield Cup loss, Niemann and Carlsen met again in the sixth round of the online Julius Baer Generation Cup.

Carlsen resigned after making just one move and released a statement saying he would not "play against people that have cheated repeatedly in the past."

The International Chess Federation announced on September 29 that it was opening an investigation into the accusations of cheating.

Niemann has admitted to cheating in the past on Chess.com, when he was between 12 and 16 years old, but denies the most recent accusations, claiming to be "ready to play naked," if necessary.