Katusha rider Alexandr Kolobnev of Russia cycles during the eighth stage of the Tour de France 2011 cycling race from Aigurande to Super-Besse in this file picture taken July 8, 2011. Kolobnev has failed a doping test during the Tour de France, an official with direct knowledge of the situation told Reuters on Monday. Picture taken July 8, 2011. REUTERS/Stefano Rellandini (FRANCE - Tags: SPORT CYCLING CRIME LAW)