Before the start of last year's race in Rotterdam all 198 riders submitted blood tests and L'Equipe have leaked the internal UCI ranking of riders according to levels of "doping suspicion". The UCI said the list is a working document helping to steer testing, not a list of riders who have done any wrongdoing.
"The UCI has been informed that the L'Equipe newspaper was going to publish in its edition on Friday a confidential document containing the riders' individual readings following tests carried out before the start of the 2010 Tour de France," said the UCI.
"First of all, the UCI deplores that this document has come into the possession of outsiders as it is a single tool on which the anti-doping services organise their activity during the race.
"This document was reserved for the UCI and independent experts of the World Anti-Doping Agency. Such a weakness in the confidentiality is very serious and the UCI will open an inquiry to discover the origin of the leak."
The confidential document is based on data gathered from the bio passport scheme introduced in 2008 by the UCI. The index is a summary from the riders biological passport's data and a blood test carried out on July 1, two days before the start of the Tour.
The index of suspicion, established by the UCI, ranges between 0 and 10 with the latter being the highest degree. The average index of the 198 riders is 2.434.
Spain's Carlos Barredo and Yaroslav Popovych of Team RadioShack were the only two riders with the highest score of 10 while Russia's Denis Menchov, who finished third, scored nine and Belgian Juergen Van den Broeck, fifth on GC, rated at eight on the index.
Three-times Tour winner Alberto Contador, who is waiting for the Court of Arbitration for Sport to rule on his positive test for the banned anabolic agent clenbuterol, was rated at five while seven-time winner Lance Armstrong was rated at four and runner-up Andy Schleck at three.
Of the top British riders, Bradley Wiggins was at five on the index, David Millar rated at four and British sprint star Mark Cavendish at rating two.
Millar said before the start of the seventh stage of the Giro that "heads should roll" at the UCI for allowing the leak.
"It's shocking. I understand that that list should exist, that's what targeted testing is about," he said.
"This list should never have been released. The UCI, some of their people should be fired for this. A major investigation should go on into what exactly they are doing with this model."
Millar, who was suspended for two years in 2004 after admitting he took a banned performance-enhancing substance, said: "I understand I'm number four because of my misdemeanours in the past," he said.
"But this (list) just does not add up."
Cavendish reacted angrily on his Twitter feed.
"So there's a leaked 1-10 'suspicion' scale for all 2010 TourDeFrance riders. So now EVERYONE'S suspicious, but just HOW suspicious?!" he wrote.
Australian Robbie McEwen added on Twitter: "I'm all for catching cheats but draw the line at this sort of thing which could be based on 1 single wayward statistic. And who leaked it??"
But Cofidis manager Eric Boyer told Reuters: "It is greatly to the UCI's credit that they give themselves the means to fight against doping."
Tour de France director Christian Prudhomme added: "It's is an additional tool in the fight against doping. It is because cycling is a forerunner in the fight against doping that such a list exists.
"I would not like the word 'suspicion' to be associated with the sport just because, precisely, it's been fighting against doping."
France had the lowest average index of 1.23 with Britain holding an average of 3.37 for eight riders. Spain, whose anti-doping policy is often criticised, has an average index of suspicion of 3.37 (out of 32 riders) and Italy 3.7 (out of 17 riders).
Kazakhstan and Ukraine (5.33 for three riders) ranked highest whilst amongst the teams, Astana and RadioShack ranked highest.
0 Boasson Hagen, Boom, Cancellara, Gerrans, Horner, Roche, Voeckler, Aerts, Arashiro, Auge, Barry, Bellotti, Benítez, Bouet, Brutt, Cardoso, Devenyns, Dumoulin, El Fares, Geslin, Grabsch, Hunter, Koren, Lancaster, Le Lay, Le Mével, Malori, Moerenhout, Moinard, Mondory, Monier, Oroz, Pauriol, Perget, Rast, Renshaw, Roelandts, Rolland, Roux, Roy, Sprick, Taaramae, Turgot, Terpstra, Vandborg, Vandewalle, Velasco, Wegmann, Zabriskie
1 Sylvain Chavanel, Gesink, Hesjedal, Hincapie, Burghardt, Casar, Charteau, Dean, Delage, Elmiger, Fröhlinger, Fuglsang, Florencio, Hansen, Klier, Kluge, Kuchinsky, Daniel Lloyd, Lorenzetto, Maaskant, Aitor Pérez, Alan Pérez, Pineau, Plaza, Pliuschin, Tjallingii, Valls, Wynants
2 Cavendish, Freire, Hushovd, Lovkvist, Luis León Sánchez, Sastre, Frank Schleck, Capecchi, Cummings, Di Gregorio, Durán, Frank, Gadret, Gavazzi, Gustov, Kern, Minard, Navarro, Niermann, O'Grady, Rubén Pérez, Riblon, Rohregger, Spilak, Tankink, Vandenbergh, Vaugrenard, Voigt, Vorganov
3 Basso, Joaquim Rodríguez, Andy Schleck, Farrar, Kreuziger, Cunego, Ciolek, Rui Costa, Flecha, McEwen, Bole, Bookwalter, Champion, Da Dalto, De Greef, De Weert, Eibegger, Erviti, Felline, Iglinskiy, Kiryienka, Ladagnous, Monfort, Paulinho, Chris Sorensen, Szmyd, Tiralongo, Txurruka, Van Summeren, Verdugo, Wegelius
4 Armstrong, Evans, Leipheimer, Samuel Sánchez, Vandevelde, Millar, Brajkovic, Pauwels, Moreno, Fedrigo, Eisel, Garate, Grivko, Jesús Hernández, Konovalovas, Lang, Quinziato, Roberts, Vogondy
5 Contador, Ballan, Vinokourov, Wiggins, Breschel, Ivanov, Karpets, Kolobnev, Kroon, Morabito, Rojas, Nicki Sorensen, Gautier, Isasi, Noval
6 Petacchi, Gerdemann, Knees, Egoi Martínez, Reda, Santambrogio, Thomas
7 Klöden, Tony Martin, Rogers, Moreau, Hunt, Sulzberger
8 Van den Broeck, Rinaldo Nocentini, De la Fuente, Iván Gutiérrez, Hondo, Lloyd, Mayoz, Muravyev, Oss, Seeldraeyers, Siutsou
10 Popovych, Barredo