Saul ‘Canelo’ Alvarez has tested positive for trace levels of the drug Clenbuterol ahead of his middleweight title rematch with Gennady Golovkin, but the May 5 fight will still go ahead.
A statement from Golden Boy Promotions blamed it on contaminated meat in Mexico and said Alvarez now would be moving his training camp to the US.
Clenbuterol is used by asthma sufferers as a decongestant but can also help to build lean muscle and burn fat.
It is classed as a prohibited substance by the World Anti-Doping Agency (WADA).
Meat contamination has affected many athletes in Mexico over the years.
Boxer Erik Morales tested positive for Clenbuterol in 2013, while five Mexican national team footballers were flagged for the drug in 2011, but were later cleared by WADA after blaming it on contaminated food.
Daniel Eichner, the director of the WADA-accredited laboratory that did the tests, said in a statement: “These values are all within the range of what is expected from meat contamination.”
“I am an athlete who respects the sport and this surprises me and bothers me because it had never happened to me,” said Alvarez.
“I will submit to all the tests that require me to clarify this embarrassing situation and I trust that at the end the truth will prevail.”