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The spokes have stopped spinning for three-time world time trial champion Michael Rogers. On December 18, 2013, the International Cycling Union—cycling’s governing body—reported the Australian pro would be provisionally suspended following the Japan Cup Cycle Road Race due to a failed drug test for the substance clenbuterol, an anabolic agent that reduces fat and builds muscle.

Rogers told his team, Saxo-Tinkoff, he . In the weeks leading up to the Japan Cup, Rogers competed in China’s Tour of Beijing where clenbuterol-tainted meat is not uncommon. Belgian rider Jonathan Breyne, 22, also tested positive for clenbuterol at the Tour of Taihu Lake in China this year.

Although clenbuterol may not be a household name for average fans, it’s a substance with which professional athletes should be quite familiar. Michael Rogers is no exception. Alberto Contador, Rogers’ teammate at Saxo-Tinkoff, tested positive for clenbuterol at the 2010 Tour de France.

The UCI found 50 picograms of clenbuterol in Contador’s urine. That is 0.000083 percent of the 60-microgram dose recommended on the message boards of BodyBuilding.com. Given the low amounts of the drug found in his sample, many were willing to believe Contador’s story. But with rumors about the UCI and Lance Armstrong circulating, the anti-doping agencies were between a rock and a hard place, says Nicki Vance, a former director of the and the program manager for doping control at the 2000 Olympic Games in Sydney.

While some dispute the benefits of clenbuterol for cyclists, it has been on the WADA’s list of prohibited substances for many years. It is an anabolic agent that helps reduce fat, while building muscle mass, although some athletes use it to keep their weight down. Used in some countries to treat asthma patients, it is not prescribed for human used in the U.S.

“Clenbuterol is taken to lose weight while at the same time preserving/increasing muscle mass,” says Dr. Michael Puchowicz, a sports medicine physician for the Arizona State University Health Services and author of the blog, an open notebook on cycling and science. “Pills seem to be the most commonly advertised form on the internet, however, it wouldn’t be surprising if an athlete attempted to use an IV form for faster clearance times.”

“Cyclists are under immense pressure to continuously manage their weight since power to weight ratio is critical for success in cycling,” Puchowicz says. “The use of clenbuterol would not be for race day performance enhancement but as part of a year round weight management strategy.”

Though athletes have used clenbuterol to cheat, it is a reality that some meat producers use clenbuterol to promote growth in livestock, and when eating meat outside the U.S. and Europe, it is possible for clenbuterol to enter the food chain and result in athletes testing positive.

In November 2011, WADA warned athletes of the dangers of contaminated meat in China and Mexico. The doping agency advised: “Eat only in restaurants and cafeterias that have been approved by your federation and/or event organizer. Furthermore, when eating outside these designated cafeteria and restaurants, always try to eat in large numbers.”

Test results can reveal the level of clenbuterol in an athlete’s sample, but not necessarily its origin. Under the WADA Code’s strict liability rule, athletes are responsible for the substances found in their bodies—regardless of whether they ingested them accidentally. And with the Contador case as precedent, WADA may be unwilling to suddenly act more leniently for Rogers.

However, if Rogers is able to prove how the drug entered his system, he may be able to clear his name. Historically, this has been difficult to prove with clenbuterol reportedly consumed from tainted meat.

“Cycling, with the stigma of the Lance Armstrong saga, we’re in a different situation,” 2004 Tour Down Under winner Patrick Jonker told Fox Sports (Australia). “I don’t think they will clear him lightly, but if Michael Rogers can prove to the authorities that it was a case of accidentally being ingested, then I hope he’ll be cleared and be able to continue his career because he’s a fantastic ambassador for the sport.”

Regardless of the prevalence of clenbuterol-tainted food in certain parts of the world, WADA’s anti-doping rules are well known in the professional cycling community and so are the dangers of ingesting meat in China.

“These are professional riders under the care of professional team doctors, both of whom have the responsibility to ensure that the athlete is not accidentally exposed,” Dr. Puchowicz says. “With such a high profile case like Contador’s clenbuterol positive it’s hard to imagine that both the riders and doctors would be caught unaware.”