|Last year's Tour winner Alberto Contador tested positive for clenbuterol but was later cleared by the Spanish cycling federation [GALLO/GETTY]
The International Cycling Union (UCI), cycling's governing body, admitted on Friday to estimating the 'doping risk' of each rider at last year's Tour de France, but regretted that the 'secret' document had been made public.
French daily newspaper L'Equipe published a list created by the UCI after blood samples taken two days before last year's race were compared with evidence already available on the riders' biological passports.
An 'index of suspicion' was created for all 198 riders from the Tour on a grade of 0-10, with 10 being the highest level of suspicion and 0 being the lowest.
The UCI defended the list saying it was a 'working document' to help steer testing, and not a list of riders who have committed any offence.
"The document ... was meant for the UCI and independent observers of the World Anti-Doping Agency (WADA). We will investigate to see how such a document has leaked," a UCI spokesman said on Friday.
Tour race director Christian Prudhomme said the existence of such a list only served to underline how seriously the fight against doping is being taken in cycling.
"It's because cycling is a forerunner (in the fight against doping) that there is a list,'' Prudhomme said.
"There is no secret index. There is a list made by one of the only three international federations that uses the biological passport. A tool, certainly a plus, in the fight against doping.''
Two riders were listed at 10, one at 9 and several more at 8. Most of the riders scored below 4.
The ratings were based on readings drawn from each rider's biological passport profile before the Tour, including the latest blood tests on July 1, two days before the start of the race.
Although cycling, and especially the Tour itself, have been rocked by doping scandals over the years, Prudhomme said the sport is making progress in eradicating doping.
"You shouldn't turn things around and again associate the word 'suspicion' to a discipline which is fighting (against doping),'' he said.
"Only those (sports) which have the biological passport can have (a list).''
But several cyclists criticised the existence of the list.
Sprint champion Mark Cavendish of Britain, a multiple sprint-stage winner at the Tour, expressed his view on Twitter.
"So there's a leaked 1-10 'suspicion' scale for all 2010 Tour De France riders,'' he said.
"So now EVERYONE'S suspicious, but just HOW suspicious?!"
Mark Cavendish on Twitter
"So now EVERYONE'S suspicious, but just HOW suspicious?!''
Former Cofidis rider Cedric Vasseur, who was president of the riders' union before resigning two years ago, mocked the UCI on his Twitter account.
"I guess next year UCI will indicate the risk level of each rider on his bike with an "Approved by UCI'' stamp... Same for the Team cars..,'' he said.
Vasseur was banned from the 2004 Tour while under investigation for suspected doping and later cleared.
There was one doping case at last year's Tour, with winner Alberto Contador testing positive for clenbuterol during a rest day. He blamed the finding on eating contaminated beef and was cleared by the Spanish cycling federation. Contador's case is currently under appeal at the Court of Arbitration for Sport.
The list was handed to UCI anti-doping officials at the race, as well as drug-testing observers from the World Anti-Doping Agency. WADA confirmed to news agency AP that its observers had received the list from the UCI during the race.
"WADA has been informed by the UCI of the provision of this list to the Independent Observer (IO) teams who were present at the 2010 Tour,'' WADA spokesman Terence O'Rorke said in an email.
"We are enquiring as to whether any leak may have emanated from the IO team.''
Scores of 0 and 1 on the UCI list indicated riders who were considered to have extremely clean records, according to L'Equipe, while rankings between 2 and 4 were based on passport profiles that fluctuated at a specific time but were otherwise normal.
Scores ranging from 6 to 10 indicated a high level of circumstantial evidence pointing to potential doping because of a recurrence of fluctuations in passport profiles or alleged doping at previous races such as the Giro d'Italia and Spanish Vuelta, L'Equipe said.
One example of a fluctuating passport profile is a sudden drop in haemoglobin in the weeks leading up to the Tour. This constitutes circumstantial evidence, because it could indicate a rider extracting his own blood and then reinjecting it to boost performance.
Variations in hematocrit levels were also monitored, a standard part of anti-doping procedures in cycling.