Norwegian multiple world chess champion Magnus Carlsen and American Hans Niemann, accused of cheating at an event last year, have buried the hatchet and are ready to face off again, online platform Chess.com said Monday.

"Since June, both sides have negotiated privately in a good-faith effort to resolve their issues and allow the chess world to move forward without further litigation," Chess.com said in a statement.

"We are happy to share that all sides have reached an agreement."

The fallout between the pair dates back to September when 20-year-old Niemann defeated Carlsen at the Sinquefield Cup, an annual match-up held in St. Louis, Missouri.

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

That claim was later echoed by international grandmaster Hikaru Nakamura and 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.

In June, a US federal judge dismissed a lawsuit for $100 million in damages filed by Niemann over the row.

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.

Niemann has said he was ready "to strip naked" to prove his skill.

"I acknowledge and understand Chess.com's report, including its statement that there is no determinative evidence that Niemann cheated in his game against me at the Sinquefield Cup. I am willing to play Niemann in future events, should we be paired together," Carlsen said in a statement, acknowledging the findings to that effect of a Chess.com public report.

The report in October "found no determinative evidence that (Niemann) has cheated in any in-person games".

Chess.com quoted Niemann as saying: "I look forward to competing against Magnus in chess rather than in court."

Regarded as the greatest player this century, Carlsen decided not to play in the last world chess championships in Astana, Kazakhstan, which saw the crowning of Chinese grandmaster Ding Liren against Russia's Ian Nepomnyachi.