Rock legend Sting started the 20th Great River Race with a bang today.

The lead singer of The Police is in town with his band to play a sell-out concert at Twickenham Stadium tonight.

But before the gig he was in Richmond to fire a cannon to start the race, commonly known as London's river marathon.

With his trademark blond hair and tight fitting t-shirt Sting was easily identifiable and was quickly mobbed by photographers and adoring fans.

Wife Trudie Styler was also at his side to offer support, and help keep the paparazzi at bay.

The race itself involved some 280 boats and 1,700 competitors rowing the 22-mile course. Sting, who confessed he had never rowed in his life, said: "I think it is an important event and I wish all the competitors good luck. "I've got a job to do now and a bigger one tonight."

Starting in Ham the flotilla passes under bridges in Wandsworth and central London before finishing in Docklands about 4pm.

Olympic gold medallists Greg Searle and Gary Herbert are rowing as part of a team in the Oxford University boat, Old Balliol, against a Cambridge crew.

Both university boats are replicas of the "fixed-seat gigs" which were rowed in the first Oxford v Cambridge Boat Race in 1829.