London: The World Cup of chess has been engulfed in a race row after a grandmaster claimed he was told he could not wear shorts because he "looked like a gypsy".

Anton Kovalyov, of Canada, stormed out of the $US1.6 million event minutes before his third round match on Sunday.

Kovalyov, 25, had turned up wearing the same stripy shorts he wore in the previous round when he knocked out Viswanathan Anand, India's former world champion.

But 15 minutes before the start of play, Kovalyov was accused of breaking the dress code imposed by the game's world governing body Fide, and ordered to change into long trousers.