16 May 2012 Last updated at 13:56

Lamont Peterson ready to fight to clear name

Lamont Peterson and his trainer Barry Hunter talk to the BBC's Richard Conway in Washington as the boxer insists he did not try to cheat despite failing a drugs test.

The 28-year-old's light-welterweight bout with Khan was due to take place on Saturday, but was called off when the American tested positive for synthetic testosterone, which Peterson says he took for medical reasons.