![](https://static.standard.co.uk/s3fs-public/thumbnails/image/2018/11/29/12/MagnusCarlsen.jpg?width=460&auto=webp)
Reigning chess world champion Magnus Carlsen
(Picture: AP)World chess champion Magnus Carlsen has for the first time openly accused fellow player Hans Niemann of cheating.
The longtime world number one called cheating “a big deal and an existential threat to the game,” in a strongly-worded statement shared on social media on Monday.
The Norwegian said he would not play Mr Niemann again after the 19-year-old dominated their Sinquefield Cup clash last month while playing with the unfavoured black pieces.
Mr Carlsen resigned from the St Louis tournament, and has now said his rival did not appear “tense” and was not “fully concentrating on the game in critical positions”.
My statement regarding the last few weeks. pic.twitter.com/KY34DbcjLo
— Magnus Carlsen (@MagnusCarlsen) September 26, 2022
The pair met again in the online Champions Chess Tour with the 31-year-old resigning after only one move.
The teenager has admitted cheating online twice, when he was 12 and 16, but has strenuously denied ever cheating over the board, and even said he was willing to play nude to prove his good faith.
Mr Carlsen said he understood his actions may have “frustrated many”.
“I believe that Niemann has cheated more — and more recently — than he has publicly admitted,” he wrote.
Day 2 #FTXCryptoCup #Chesschamps pic.twitter.com/E91Vyhc26n
— Hans Niemann (@HansMokeNiemann) August 16, 2022
“I’m frustrated. I want to play chess. I want to continue to play chess at the highest level in the best events.
“I believe that cheating in chess is a big deal and an existential threat to the game. I also believe that chess organizers (sic) and all those who care about the sanctity of the game we love should seriously consider increasing security measures and methods of cheat detection for over the board chess.”
Mr Carlsen said he nearly pulled out of the Sinquefield Cup when Mr Niemann was added as a late entry - but decided to play anyway. His results were annulled and the series was won by French-Iranian grandmaster Alireza Firouzja.
The events do not seem to have upset Mr Carlsen’s form and he recently clinched the Julius Baer Generation Cup.
Mr Niemann has not provided a public statement in response.