SPORTS hero Sir Steve Redgrave was given the shock of his life yesterday - when pranksters from TV's Top Gear invaded his garden.

Presenters Jeremy Clarkson, Richard Hammond and James May gave the rower's Marlow Bottom home a cowboy builder makeover - but it was all in the name of a good cause.

After being kept away while they set their trap by his agent, and his wife, Lady Ann Redgrave, Marlow-born Sir Steve came back to a makeshift disaster zone.

Neighbours heard an explosion amid the good natured melee that followed.

A digger was left lopsided in a ditch to put the final touches on Sir Steve's construction nightmare.

The stunt was in aid of Sport Relief, BBC Sport's fundraising initiative, of which Sir Steve is a strong supporter.

But BBC chiefs remained tight-lipped over the full details of the elborate prank - and urged viewers to tune in to see the full results on March 14. The star's mouth dropped to the floor when he saw what had happened - before the cheeky presenters appeared.

Its editor, Carl Doran, who helped co-ordinate yesterday's tea-time prank, said: "He knew absolutely nothing about it - we really set him up. But we knew he'd see the funny side "Steve's a huge supporter of Sport Relief and has devoted a lot his spare time to helping the charity over the years."

Sport Relief is on the BBC from March 14 to 16.

Since winning five golds in a row Sir Steve - considered to be Britain's best ever Olympian - has thrown himself into charity work, This year the star joined his Steve Redgrave Trust with Sport Relief to become the Steve Redgrave Fund.

The trust raised £5m in five years for sports projects with work particularly focused on schools to tackle problems like obesity and lack of confidence.

Recently Sir Steve has also thrown his backing behind the Fairtrade movement, which aims to give a better deal to third world producers.

Sport Relief organises programmes for deprived communities in the UK and overseas.