Nick Kyrgios risked causing controversy once again after he was knocked out of the second round of the Shanghai Masters after apparently serving without any effort.

The Australian tennis player, ranked 14 in the world, also appeared to walk off the court before his opponent, the world number 110 Mischa Zverev, had returned the ball to him and, one occasion seemed to make no attempt to return a Zverev serve. He lost the match 6-3, 6-1.

On Tuesday, Kyrgios claimed to be "bored" as he beat the world number 29 Sam Querrey in the first round.

Last year, he was fined $1500 for calling the tournament "a circus" and criticising the "f**king surface". Four days ago, however, he beat David Goffin to win the Japan Open. Previously, he sparked criticism after apparently refusing to try at Wimbledon in 2015 in protest at receiving a code violation for swearing during his fourth round defeat to Richard Gasquet.