A protester has entered the tennis court and set his arm on fire during a Laver Cup match in London, hours before Roger Federer's final game before retiring.

Wearing a white shirt with a message about private jets, the man made his way onto the court and sat down near the net.

He set his arm on fire before being carried away by security guards.

It forced the delay of the second set of Stefanos Tsitsipas's 6-2, 6-1 victory for Team Europe over Diego Schwartzman of Team World.

"It came out of nowhere … I never had an incident like this happen on court," Tsitsipas said.

"I hope he's all right."

Tsitsipas spoke to the chair umpire to make sure it would be safe to continue to play and asked that a mark left on the court be cleaned up.

Laver Cup organisers said the man had "been arrested and the situation is being handled by the police". 

This event follows a number of instances of high-profile tennis matches being interrupted in recent years, including the 2009 final at Roland Garros, when a man went up to Federer and tried to put a hat on his head.

At this year's French Open, a protester wore a T-shirt with the message "we have 1028 days left" and attached herself to the net with metal wires and glue and kneeled on the court during the men's semifinal.

AP