A US federal judge on Tuesday dismissed a lawsuit filed by chess player Hans Niemann, who was seeking $100 million from those who accused him of cheating, including former world champion Magnus Carlsen.

"We are pleased the Court has rejected Hans Niemann's attempt to recover an undeserved windfall in Missouri federal court," said Craig Reiser, Carlsen's attorney.

The 20-year-old American, hailed as a prodigy by those close to him, had filed a suit for libel in a Missouri state court in a case that shook the chess world and has gripped millions of Internet users.

It all started on September 5, 2022, when Niemann defeated Carlsen in the Sinquefield Cup, an annual chess tournament held in St. Louis, Missouri.

The 32-year-old Norwegian Carlsen, a five-time world champion, then withdrew from the tournament with a bang, accusing his opponent of cheating.

His claims were later echoed by international grandmaster Hikaru Nakamura and the world's leading online chess platform, chess.com, suggesting that Niemann had likely cheated at least 100 times online.

Niemann has admitted to cheating on chess.com when he was between 12 and 16 years old, but denies having continued and said he was ready "to strip naked" to prove his skill.

The International Chess Federation (FIDE) opened an investigation last September into the affair, described by many as one of the biggest scandals in the history of chess.

Since it broke out, Niemann has continued to play in tournaments, although he has lost some ground in international rankings.

Carlsen decided not to play in the last world chess championships in Astana, the capital of Kazakhstan, which saw the crowning of the Chinese grandmaster Ding Liren against the Russian Ian Nepomnyachi.

Carlsen is still considered the greatest chess player of the 21st century.