Gdańsk: World chess champion Magnus Carlsen said he believed Hans Niemann had “cheated more - and more recently - than he has publicly admitted”, adding he no longer wanted to play against the American and any rivals who repeatedly cheated in the past.

The 31-year-old Norwegian resigned at the Julius Baer Generation Cup last week after one move against Niemann, who lags him by almost 200 Elo points - the rating system used to calculate the relative skill levels of players.

“So far I have only been able to speak with my actions, and those actions have stated clearly that I am not willing to play chess with Niemann,” Carlsen said in a statement on Twitter.

Carlsen, world champion since 2013, also withdrew from the Sinquefield Cup in St Louis, Missouri earlier this month after unexpectedly losing to the 19-year-old, sparking a furore of comments and allegations that Niemann had cheated.

Niemann has denied any wrongdoing in over-the-board games.

“When Niemann was invited last minute to the 2022 Sinquefield Cup, I strongly considered withdrawing prior to the event. I ultimately chose to play,” Carlsen said.

Niemann has previously been banned from chess.com for cheating online after admitting he had not played fairly in non-competitive games on the website in his youth.

“I believe that Niemann has cheated more - and more recently - than he has publicly admitted,” Carlsen said on Monday.