Former Olympic sprint champion Linford Christie crashed head-on into a taxi carrying a pair of newlyweds while driving the wrong way down a major road, a court has heard.

The former 100m champion allegedly clambered from his badly damaged Audi A8 moments after the collision and appeared to go into shock, rolling around on the ground near the wreckage.

Witnesses later recalled the distressed Christie saying "Oh my God, it's all my fault", jurors were told.

Aylesbury Crown Court heard that the 51-year-old set off to buy a pint of milk from a Tesco Express garage and was driving back towards Amersham, Buckinghamshire, when he found himself on the wrong side of the A413.

A matter of eight seconds later, his car - with a personalised number plate 100 RUN - hit the silver Mercedes travelling in the opposite direction, it was alleged. The taxi was propelled on to a grass verge while the dark-coloured Audi came to a halt in the middle of the carriageway.

Christie, who had recently moved to the area and was on his way back to his girlfriend's home, was able to walk away from his vehicle but newly married Peter Ashton had to be dragged from the taxi following the late-night crash last May.

Opening the case, Prosecutor Nigel Ogborne said Mr Christie had failed to buy his milk that evening because the petrol station was closed. He told the court Christie was making his way home at between 11.30pm and 11.40pm when he ploughed into the taxi.

"He drove for some 185 metres and, the prosecution say, he drove on the wrong side of the road," Mr Ogborne told the court. "He was driving on the opposing carriageway and a car was driving the other way and there was a head-on collision."

Christie, dressed in a charcoal-grey suit, blue and white check shirt and a dark waistcoat, sat quietly at the back of the court as the case was outlined against him.

The sportsman, of Sherland Road, Twickenham, west London, denies one count of dangerous driving on the A413 Amersham Road in Chalfont St Peter, Buckinghamshire, on May 8 last year.