Nick Kyrgios has been stripped of his prize money at the Shanghai Masters and fined $10,000 for unsportsmanlike conduct after another controversial retirement.

The Australian quit midway through his match with Steve Johnson on Tuesday, citing illness and a shoulder injury for his decision.

Kyrgios walked off court after losing the first-set tie-break in China, having previously been heard telling the umpire of his plan should he fall behind.

After Johnson fired down an ace on set point, Kyrgios – who had already received a point penalty for an audible obscenity - walked over to shake the American's hand, leading to boos from the crowd.

He later apologised on social media but the ATP has taken action against his behaviour, while also taking away his $21,085 prize money for failing to attend a post-match medical.