It emerged earlier this week that Lamont Peterson, who controversially beat Amir Khan in December to capture the Bolton fighter's WBA and IBF junior welterweight titles, had tested positive for a banned steroid. The news cast doubt over the pair's May 19 rematch in Las Vegas until Golden Boy Promotions and Khan himself confirmed that the bout has been scrapped due to Peterson's use of synthetic testosterone and his inability to get a boxing license in Nevada.
In an earlier news brief, Khan said "the truth's come out now and it just proves that Lamont Peterson was a cheat really."
Peterson's publicist, Andre Johnson, insisted the 28-year-old had done nothing wrong and would fight to clear his name.
He told Sky Sports News: "Lamont Peterson has been boxing for 18 years. In 18 years, barring this incident, he's never tested positive for anything - and after this incident. Three other tests were taken that he tested negative for.
"We're going to get to the bottom of this and do everything in our power to clear Lamont's name. Lamont will be fighting very soon.
"We're extremely disappointed. We wanted to make this fight happen. We're sorry it didn't happen.
"Lamont is not a cheat. He is not a steroid abuser. There's no evidence of anabolic steroid abuse in his body or in his system. The doctor that saw him in Nevada determined he has low testosterone levels. There's no way a guy with his type of level can test positive for an anabolic steroid that is testosterone-based."
He added: "Lamont did nothing wrong. He's not a doper. He's not a cheater.
"He's distraught. He wanted to clear his name and do what he was born to do - fight.
"Mark my words: Lamont Peterson is a man of tremendous character - he's a fighter. We will fight to get the truth."
On the possibility of a future rematch against Khan, Johnson said: "We would love to fight Amir Khan again. That's going to be up to Amir Khan.
"We don't have a problem. We would love to make it happen. That's why he accepted the opportunity to fight him this time - because the fans wanted it."