Tour de France champion Alberto Contador's claim that the steak he ate is to blame for his positive doping test is plausible, experts say, since the drug he's accused of taking is sometimes illegally given to beef cattle.
Contador, a three-time Tour de France champion, blamed contaminated steak for his positive doping test, vowing Thursday to clear his name so that cycling's latest drug scandal doesn't "destroy everything that I have done."
The Spanish rider was provisionally suspended after a World Anti-Doping Agency lab in Germany found a "very small concentration" of the banned substance clenbuterol in his urine sample on July 21 at the Tour, according the International Cycling Union, the sport's governing body.
"It is a clear case of food contamination," Contador told a news conference in his hometown near Madrid, during which he appeared close to tears several times. "I am sad and disappointed but hold my head high."
Clenbuterol is often used to speed up growth and increase muscle mass in animals, including chickens, cattle and pigs. And it's typically been used by people for bodybuilding.
The UCI said the amount of clenbuterol in Contador's sample was "400 time[s] less than what the antidoping laboratories accredited by WADA must be able to detect."
Both Contador's A and B samples tested positive, and the cyclist has been "formally and provisionally suspended," the UCI said.
"I think this is going to be resolved in a clear way," he added. "With the truth behind you, you can speak loud and clear, and I am confident justice will prevail."
Contador's former team is backing the UCI's decision to provisionally suspend him.
Contador won his third Tour this summer riding with the Astana team. He has since joined the Saxo Bank-SunGard team.
Astana said in a statement Friday that team officials are "now expecting further explanations from Alberto Contador and support the UCI who suspended him provisionally."
Contador said the beef was brought across the border from Spain to France by a Spanish cycling organizer, Jose Luis Lopez Cerron, during a Tour rest day and at the request of the team's chef. Cerron said earlier Thursday on Spanish radio that he was a friend of the chef, who had complained of poor-quality meat at the hotel where the team was staying.
Lopez Cerron said he bought filet mignon for the team in the Spanish border town of Irun on his way to Pau, France.
Spain has had several past reports of health problems linked to clenbuterol after people ate beef and veal containing it. In the 1990s, more than 100 people had symptoms including increased heart rate, muscle tremors, nausea, headaches and anxiety blamed on the drug.
The drug is legal in Europe only for animals that aren't intended for human consumption, but experts say clenbuterol is sometimes found illegally in animal feed to produce more lean meat. It's usually stored in the animals' liver or muscle tissue.
Contador said he ate the meat on July 20 and again on July 21. He called his suspension by the UCI "a true mistake."
"The idea of anyone questioning my Tour victory does not worry me," Contador said. "I am not going to let something like this destroy everything I have done."
He said he learned of the test results on Aug. 24 and met with UCI doctors two days later.
Contador was provisionally suspended after a World Anti-Doping Agency lab in Germany found a "very small concentration" of the banned substance clenbuterol in his urine sample taken on July 21 at the Tour.
After the doping case was revealed Thursday, the Spanish rider said contaminated meat must have caused the minute traces of the banned stimulant.
"On the 26th we talked at length about how all this had happened. The UCI itself told me to my face that it was a case of food contamination," Contador said.
Contador beat Andy Schleck of Luxembourg by 39 seconds in winning his third Tour in four years.
"What a crazy day in cycling with the news about Contador," Schleck said on Twitter. "I only heard about it in the press. I hope he is innocent and I think he deserves the right to defend himself now."
The allegations are the latest to hit a sport whose credibility has been battered by doping scandals. Within hours of Contador's case becoming public, the UCI announced that two Spanish riders failed drug tests during the Spanish Vuelta in September -- runner-up Ezequiel Mosquera and David Garcia. The UCI said they tested positive for hydroxyethyl starch, which increases blood volume.
With seven-time Tour champion Lance Armstrong now back in retirement, Contador is cycling's biggest star, so it could be devastating for the sport if the Spanish rider is found to have cheated.
The UCI's statement gave no indication of whether Contador will be stripped of his latest Tour title or be banned.
"The UCI continues working with the scientific support of WADA to analyze all the elements that are relevant to the case. This further investigation may take some more time," the statement said.
The head of cycling's world governing body, Pat McQuaid, attended the UCI Congress meeting in a downtown Melbourne hotel on Friday. He told The Associated Press he was "completely limited" in what he could say about the Contador case, so "I'm saying nothing."
If Tour officials strip Contador of his title, he would be just the second cyclist so punished. The first was American Floyd Landis, who was stripped of his 2006 Tour title after a positive test. For years, Landis denied doping but admitted this spring that he used performance-enhancing drugs.
By investing millions of dollars in recent years in what is widely regarded as one of the most stringent anti-doping regimes anywhere, cycling authorities hope to eradicate widespread doping by riders, particularly in their showcase race. Although just 27, Contador is already the greatest rider of his generation. His victories at the Tour starting in 2007 and at other major races were seen as a possible break from cycling's dirty past.
"This is serious and this case needs to be clarified," Pierre Bordry, the outgoing leader of France's anti-doping agency, told RTL radio. "Clenbuterol is a forbidden substance, whatever the amount which is detected. If they really found it, it's forbidden."
WADA director general David Howman told The Associated Press that testing positive for even the most minute amounts of clenbuterol could be enough to sanction an athlete, although he declined to discuss the specifics of Contador's case.
"The issue is the lab has detected this. They have the responsibility for pursuing. There is no such thing as a limit where you don't have to prosecute cases. This is not a substance that has a threshold," said Howman, reached by telephone as he was changing planes in Dubai on his way to the Commonwealth Games in India.
"Once the lab records an adverse finding, it's an adverse finding and it has to be followed up. Clenbuterol is a substance that has been used for over 20 to 30 years," he added. "It is not anything new. Nobody has ever suggested it is something you can take inadvertently."
Douwe de Boer, a Dutch anti-doping expert hired by Contador to study his test, said the rider told him that smaller traces of clenbuterol were also found in his urine in the two days after the positive result but were so minute that the UCI classed them as negative.
Clenbuterol has anabolic properties that build muscle while burning fat. It is commonly given to horses to treat breathing problems. In medicine, it is used to treat asthma. In similar ways to stimulant drugs such as amphetamine or ephedrine, it can increase the heart rate and body temperature.
Doctors said it would have been nearly impossible for Contador to have received any performance boost from eating clenbuterol-spiked meat.
"The amounts [of clenbuterol he consumed] would be incredibly small unless you were eating vast quantities of meat," said Dr. Andrew Franklyn-Miller, a sports medicine expert at the Centre for Human Performance in London and a team doctor for Britain's rowing team.
"It's very unlikely that the night before a stage in the mountains, anyone would be eating three or four steaks," said Franklyn-Miller, who said cyclists typically eat carbohydrates before a race because they are easier to digest.
Michael Audran, a doping expert who works closely with the World Anti-Doping Agency, said the amount of clenbuterol found in Contador's samples was so small it is unlikely the cyclist was abusing the drug. He said the contamination theory is the only possible explanation for the positive result.
Other experts said the doping tests need to be refined to include a threshold amount for clenbuterol, not simply whether or not the drug is present.
In Contador's case, "the quantity is the key to judging" whether it was a case of possible doping or consuming the drug by eating meat, said Giuseppe Banfi, a sports biochemistry expert at the University of Milan. "We don't have the proper parameters right now to know if this was illicit use."
"I 100 percent give Alberto fully the benefit of the doubt," said British rider David Millar, himself banned for two years in 2004 after admitting to using the banned blood-booster EPO. "It doesn't make much sense in that it was a rest-day control and it's a micro-dose ... Alberto gets controlled every day when he's in the yellow jersey and that would have come up the day before or after the race."
Information from The Associated Press was used in this report.