Andre Berto tests positive

Former welterweight titleholder Andre Berto has tested positive for a banned substance, and his June 23 rematch with fellow former titlist Victor Ortiz has been canceled, according to Golden Boy Promotions CEO Richard Schaefer.

Berto tested positive for the steroid norandrosterone, a source with direct knowledge of the test results told ESPN.com on Friday.

Promoter Lou DiBella told ESPN.com he was unsure of what Berto tested positive for but confirmed the result.

"I know he tested positive," DiBella said. "I have nothing else to say. I don't know all of the details so I have nothing else to say."

"Obviously, we are disappointed that Berto's 'B' sample came back positive," Schaefer, Ortiz's promoter, told ESPN.com. "I was informed late Saturday of the 'A' sample testing positive and urged an immediate testing of the 'B' sample. We just got the results that the 'B' sample tested positive as well. It's unfortunate. We have to see what happened because I don't know.

"This is obviously a very unpleasant situation to say the least, but at the same time, there is no room for any form of performance-enhancing drug use in boxing. I am not accusing Berto of anything, but that happens when you want to clean up the sport and you agree as a fighter and promoter to go through these kinds of procedures. I hope this will lead athletes to be more careful with what they eat or drink or take. Everybody needs to educate themselves more about what is permitted and what it is not permitted. But if it takes two or three or four fights to be canceled, so be it. There can be zero tolerance for the use of banned substances."

Berto denied using a banned substance.

"At the present time, I cannot explain the positive drug test, which was provided as part of a voluntary anti-doping program in which I agreed to participate," Berto said in a statement. "I know that I have never used any steroids or other banned substances, and I am investigating all possible causes of the positive test with my attorney, Howard Jacobs. I have never cheated, and all of my success has come from hard work and dedication."

Jacobs has requested the complete laboratory documentation package, including all chain of custody documentation and scientific data supporting the lab's summary report.

Berto has had Victor Conte, founder of the notorious Bay Area Laboratory Co-Operative, in his training camp for this fight.

Conte, however, denied he had any involvement in the positive test.

"Andre Berto's positive test for (norandrosterone) has absolutely nothing to do with me or any supplements I provided. Likely trace contamination," Conte tweeted. "Andre has admitted to taking supplements other than what I provided without my knowledge. Apparently, something was contaminated."

Ortiz and Berto agreed to use the Las Vegas-based Voluntary Anti-Doping Association for random blood and urine testing in the lead up to their fight at the Staples Center in Los Angeles. Showtime had made the bout the centerpiece of its boxing schedule for the first half of the year.

Berto submitted to a random urine test May 2. The "A" test came back positive last week. The "B" sample also came back positive Friday, triggering VADA to alert the California State Athletic Commission, DiBella and Schaefer.

"We did our job. We stand by the integrity of the test and the testing process," said Dr. Margaret Goodman, who heads VADA and is a former chief ringside physician for the Nevada State Athletic Commission. "It's not our role to determine what comes next for Mr. Berto. At this point it would be inappropriate for me to discuss the matter further with the media."

In April 2011, Ortiz (29-3-2, 22 KOs) outslugged Berto (28-1, 22 KOs) to win a welterweight title in one of the year's most exciting fights.

In September, Ortiz was knocked out by Floyd Mayweather Jr. Berto, meanwhile, claimed another version of the 147-pound crown against Jan Zaveck but later vacated it in order to take the rematch with Ortiz rather than fight a far less lucrative mandatory challenger.

Ortiz-Berto II originally was supposed to take place Feb. 11 in Las Vegas, but Berto suffered a torn left biceps, postponing the fight to June 23 in Los Angeles.

After the fight last year, Berto accused Ortiz of using performance-enhancing drugs in his upset victory. Now it is Berto who has tested positive, an irony not lost on Rolando Arellano, Ortiz's manager.

"When you point the finger there's three pointing back at you, but we will take the high road," Arellano said. "We're going to give this guy the benefit of the doubt.

"We want to fight him and he wants to fight us, so we are going to wait until there is a complete fact finding in this case. We know what VADA has to say and we're curious what about what Berto has to say. Hopefully, there is something that went wrong. Maybe the jars got mixed up. But it doesn't look that way. Victor will go on, but this is awful for boxing fans who wanted to see another fight of the year."

Arellano said he informed Ortiz of Berto's positive test and his response was "complete and utter silence. Then he said, 'I'm going to the gym.'"

This is the second high-profile positive drug test, both conducted by VADA, before a major fight in the past two weeks. Junior welterweight titlist Lamont Peterson tested positive for synthetic testosterone following a March 19 random test in the lead up to his rematch with Amir Khan. They were scheduled to meet Saturday night in Las Vegas but the fight, also a Golden Boy promotion, was canceled last week.

Schaefer and Showtime both told ESPN.com they have no intention of canceling the card.

"This means another terrific fight that fans were looking forward to appears like it's not going to happen," Schaefer said. "I want to know what the origins of this (positive test) are. I have been told that it could have something to do with food contamination. But I'm not going to go and cancel the event. Let's learn more, let's see what will happen. In the meantime, my team is working behind the scenes to come up with an alternative opponent."

Unlike the Peterson-Khan situation, where weeks went by between the testing of the two samples, leaving Golden Boy with no time to find a replacement opponent, this time the tests were done quickly. That gives Golden Boy time to find a replacement to face Ortiz.

"We know with Peterson he had testosterone pellets injected in him. I don't know what the cause of the positive test is in this case. I only know it came back positive," Schaefer said. "But the way this was handled allows us to attempt to find a replacement opponent and have the show go on. The fact is the difference between testing dates of the 'A' and 'B' samples was a few days, not weeks.

"I appreciate the fact that (Berto adviser) Al (Haymon) informed me about the 'A' sample and we were able to get the 'B' sample tested immediately. But it's a difficult situation."