Three-time Tour de France winner Alberto Contador of Spain was suspended Thursday after failing a dope test, in the latest drug scandal to hit cycling's most prestigious event.
The cycling superstar, who won his third yellow jersey at the end of July's three-week epic, announced that he had tested positive for clenbuterol, a banned substance, but blamed it on food contamination.
The International Cycling Union (UCI) swiftly announced he had been provisionally suspended after the news broke in Australia.
The UCI said clenbuterol was detected in a urine sample taken from the Spaniard on July 21, during the second rest day in Pau at the foot of the French Pyrenees.
But world cycling's ruling body said that only a "very small concentration" of the drug had been found and that the case warranted "further scientific investigation" because the Cologne laboratory that detected the substance is known to be able to detect the tiniest traces of drugs.
"The rider, who had already put an end to his cycling season before the result was known, was nevertheless formally and provisionally suspended as is prescribed by the World Anti-Doping Code," a UCI statement said.
"The concentration found by the laboratory was estimated at 50 picograms which is 400 times less than what the antidoping laboratories accredited by WADA (World Anti Doping Agency) must be able to detect," it said, adding that testing of a second "B" sample taken at the same time confirmed the result.
There are a trillion picograms in a gram.
Contador's announcement was issued through his personal press officer as world cyclists gathered in the Australian port of Geelong for the Road Race World Championships.
"Alberto Contador is affected by a doping control at the last Tour de France on July 21, where the substance clenbuterol was found," a statement from his press officer said.
"From the time of the first communication from the UCI on August 24, Alberto Contador alleged food contamination as the only possible explanation of what happened."
The message added that Contador, one of only a handful of riders to have won the Tour de France, Giro d'Italia and Tour of Spain, has consulted with a number of experts, who have all agreed that the "tiny amount of clenbuterol detected" suggested that the cyclist has fallen victim to food contamination.
"The experts consulted so far have agreed also that this is a food contamination case, especially considering the number of (doping) tests undergone by Alberto Contador during the Tour de France.
"This makes it possible to define precisely both the time of the emergence of the substance and the tiny amount detected, ruling out any other source or intentionality."
It said Contador, 27, will give a press conference at the Hotel Las Artes in the Spanish town of Pinto at midday "in order to give his version of what happened to the public".
A banned substance which can be used to help lose weight and help breathing, clenbuterol is also known to boost performance by helping to increase strength.
The day after the July test, Contador took a huge step towards an overall win by finishing in the same time as main rival Andy Schleck of Luxembourg at the summit of the Col du Tourmalet.
At the penultimate stage time trial on July 24 he secured victory with a 39-second lead on Schleck.
Although a banned substance, positive tests for clenbuterol have resulted in different outcomes for athletes in the past.
It has been shown in the past that trace elements of the drug found in the human body can be attributed to food contamination. If it is found in larger amounts it usually points to deliberate doping.
Chinese rider Fuyu Li, who races with Lance Armstrong's RadioShack team, was also provisionally suspended after testing positive for clenbuterol in April.
He was later given support by a Dutch anti-doping expert, Douwe de Boer, who said the amount found in his body points "clearly in the direction of a contamination" and that such a low dose would not help his performance.
Tour de France organisers said they had learned about the adverse analytical finding through the UCI's statement on Thursday morning, but could take no action on the race champion as yet.
A statement from race owners ASO (Amaury Sports Organisation) said: "The UCI has indicated that further scientific investigation, with the support of the World Anti Doping Agency, is needed.
"No action can be taken until this process has been completed."
© AFP 2010