How extraordinary was Ye Shiwen's Olympic performance? A US swim coach called her 400m medley swim "disturbing". More or Less investigates.

There was controversy this week after Ye Shiwen - a young Chinese swimmer - won the 400 metre individual medley in fine style.

A US swimming coach called the performance "disturbing", implying that she may have cheated.

More Or Less investigates the numbers and finds there's no statistical smoking gun.

(Image: China's Ye Shiwen competing in the women's 200m individual medley heats swimming event at the London 2012 Olympic Games. Credit: AFP PHOTO/LEON NEALLEON NEAL/AFP/Getty Images)