A leading soccer association in Latin America has suspended five players in Mexico for failing drug tests. The players insist they unknowingly consumed beef containing banned-drug clenbuterol.

The players were removed from the CONCACAF Gold Cup last week after testing positive for clenbuterol — a drug used for boosting lean muscle mass promoting growth — is illegal in food animal production, and sports, in both the U.S. and Mexico because drug residues can cause serious health problems in humans.

PSV Eindhoven defender  Francisco Rodriguez, World Cup goalkeeper Guillermo Ochoa, defender Edgar Duenas, and midfielders Christian Bermudez and Antonio Naelson “Sinha” were all removed from the Gold Cup team after testing positive for clenbuterol during routine testing outside of Mexico City, according to press accounts.

Mexican health officials said late last week that the cases of contaminated beef are fewer than one in a million. Ochoa, the suspended goalkeeper, maintained the players’ innocence.

“We have nothing to hide,” Ochoa said. “Our conscience is clean because we haven’t done a bad thing.”

“It’s sad these things happen,” he added, according to a wire report. “These are things that could happen in any restaurant in any location, and it happened to us when we were together in training. It is bad luck. We know this is going to be cleared up, and we’re facing the situation.”

The World Anti Doping Agency will meet next week to consider changing rules on clenbuterol testing in response to the controversy surrounding Alberto Contrador, a Spanish Tour de France-winning cyclist who rested positive to the drug but was subsequently cleared by authorities after they ruled that his positive result was due to consumption of contaminated steak.