The world governing body of chess has had its financial dealings halted amid allegations its scandal-hit president facilitated the funding of Islamic State terrorists.
Fide, the Lausanne-based federation which runs the game, disclosed on Tuesday that Swiss bank UBS closed its accounts after finally losing patience with its failure to depose Russian millionaire Kirsan Ilyumzhinov.
Mr Ilyumzhinov, who was once part of Vladimir Putin's inner circle, was placed on a US wanted list in November 2015 for allegedly being involved in oil deals which left a financial trail to the terror group Isil via the Syrian government.
But despite repeatedly denying the allegations, and claiming he is the victim of a US-led plot to topple him, Mr Ilyumzhinov has been unable to clear his name.
In a letter published on the Fide website, treasurer Dr Adrian Siegel revealed UBS had shut its bank accounts and the federation faces a "serious problem" paying bills just weeks before the Candidates, its flagship world championship play-off tournament in Berlin which has a prize fund of $460,000.
Dr Siegal laid the blame squarely on Ilyumzhinov, saying the allegations "severely damaged Fide's business activities".
"It was only a matter of time before we faced this serious problem," he said. "In summary, Kirsan Ilyumzhinov's problems severely damaged Fide's business activities and we have to look for a new banking connection."
The decision by UBS, the world’s largest wealth manager, comes amid a wider attempt in Switzerland to clean up the reputation of its banking sector, which has long been accused of turning a blind eye to criminal activity.
It is doubtful whether any other bank will agree to take on Fide's accounts while Mr Ilyumzhinov remains president. Mr Ilyumzhinov, an eccentric former politician who claims he was abducted by aliens twice, has reigned as the king of chess for 23 years.
But after the US Department of Justice's decision to investigate him, rumours of back-stabbing and in-fighting began to swirl around Fide.
The embattled head was unable to attend the 2016 world chess championship held in New York for fear of arrest and became increasingly sidelined.
Last year, Fide officially announced Mr Ilyumzhinov had stepped down but then backtracked when the former head of the Russian semi-autonomous republic of Kalmykia insisted it was "fake news".
David Kramaley, founder of chess learning site Chessable.com, said: "This kind of turmoil at the top of chess has got to stop for the good of the game.
The game needs stable leadership." In 2014 Mr Ilyumzhinov overcame an attempt to unseat him led by his US-based rival Garry Kasparov amid widespread allegations of vote-rigging, allegations Mr Ilyumzhinov and Fide denied.
In a comment a spokesperson for UBS said: "We can't comment on whether individuals or organizations are clients of UBS. We follow all laws and regulations that are applicable to us."