British Olympic swimmer Marco Loughran has described a recent road rage incident that left him in hospital as a "cowardly attack".

The 26-year-old and his girlfriend Jeanette Ottesen, who is a world butterfly champion for Denmark, suffered injuries when they were attacked through their car window.

Loughran has revealed that the brawl occurred after a male van driver accused Ottesen, who was driving, of taking too much time to pull off when a traffic light turned green.

The Olympian suffered cuts to his eyebrow and head, as well as damage to his ear, shoulder and mouth, which resulted in four chipped teeth.

Ottesen also broke one finger and sprained another while trying to protect her boyfriend when he was approached through the car window.

"Denmark is a gorgeous place to live and everyone has been shocked by what's happened," PA quotes Loughran as saying.

"It was a cowardly attack and I'm just thankful that the seven or eight punches I took weren't stabs to the head because that doesn't bear thinking about. I'm on the mend now but Jeanette is so upset about it all."

Loughran competed for Britain at the London 2012 Olympics.