British Prime Minister David Cameron says it's time FIFA introduced goal line technology.

Cameron threw his weight behind calls for the use of video technology in football, after Frank Lampard's goal in England's World Cup defeat by Germany was disallowed despite clearly crossing the line.

The PM said he was "very disappointed" to see England go out of the World Cup, after watching the second half of Sunday's 4-1 defeat with German Chancellor Angela Merkel - who also said that the Lampard goal should have been allowed to stand.

At a press conference at the end of the G20 summit in Toronto, Mr Cameron suggested that the use of cameras to help referees judge tough decisions should be considered.

"I do think that the use of technology in sport can be a bonus," said the PM.

"I'm a keen follower of cricket and tennis and I think the third umpire has been a great thing and the machines that bleep at Wimbledon are quite handy too.

"Maybe that's something that football could now have a look at."