Apparently, Floyd Mayweather knew exactly what he was talking about when he said "boxing is a very, very dirty sport" and "there's so much cheating going on." According to mulitple reports, former welterweight champion Andre Berto has tested positive for a banned substance, putting his highly-anticipated June 23 rematch with Victor Ortiz in jeopardy. Berto is the second fighter in less than a month who tested positive for a banned substance by the Voluntary Anti-Doping Association [VADA], joining jr. welterweight champion Lamont Peterson, who tested positive for synthetic testosterone pellets, which forced the cancellation of his rematch with Amir Khan that was set to take place this Saturday.

The irony is that both Berto and Peterson were the ones requesting the services of VADA for the additional testing. It's unclear at this point if VADA co-founder Victor Conte was still a member of Andre Berto's team, having worked with him in his previous bout. "I know he tested positive. I learned it in the last half-hour," promoter Lou DiBella would tell ESPN.com. "I have nothing else to say. I don't know all of the details, so I have nothing else to say." According to Maxboxing's Gabriel Montoya, however, Berto tested positive for Nandrolone.

UPDATE: As expected, the highly-anticipated rematch between Victor Ortiz and Andre Berto has officially been called off. Golden Boy Promotions is currently looking for a replacement. Josesito Lopez (29-4, 17 KOs), who was last seen losing a spirited and close split decision to undefeated Jessie Vargas, is rumored to be the frontrunner to land the assignment.