Amir Khan believes that Lamont Peterson's failed drug test proved that he was a "cheat".

The two were set to clash in a rematch on May 19 after the American controversially defeated the Brit in December for the WBA and IBF light-welterweight titles, but now the fight has been called off after Peterson tested positive for a banned substance.

As a result of the tests, Khan believes his claims of Peterson being a cheat were right all along.

"I'm disappointed because I trained very hard for this fight," Khan told Sky Sports News.

"It was only 10 days away from the fight where my dad came knocking on my bedroom door and said to me 'look, Lamont Peterson's failed his drug test and the fight's no longer going to happen'.

"It was a big shock for me. My head was all over the place, I really, really wanted to win my titles back and have the fight. But the truth's come out now and it just proves that Lamont Peterson was a cheat really."

Khan next hopes to be in action on June 30 and feels that Peterson will be stripped of his belts.