AURILLAC, France -- A French official said police didn't find doping evidence in a search of Russian rider Alexandr Kolobnev's hotel room.
Jean-Pascal Violet, the public prosecutor for the town of Aurillac, told The Associated Press that he has opened an investigation in connection with Kolobnev's failed Tour de France doping test.
The rider dropped out of the Tour on Monday after the International Cycling Union said a urine sample collected from Kolobnev last Wednesday tested positive for Hydrochlorothiazide, a diuretic that can also be used as a masking agent.
Kolobnev was in 69th place heading into Tuesday's 10th stage, but his Katusha team issued a statement late Monday saying he is out of the Tour after deciding to "suspend himself according to UCI rules."
The Russian issued his own statement Tuesday in which he said he wouldn't comment on the situation "for respect to the race organizers and cycling in general."
Kolobnev said he doesn't know how the banned diuretic got into his urine sample. He said he was waiting for the results of a test of his "B" sample.
Katusha manager Andrei Tchmil said Kolobnev has been temporarily suspended until the team receives the results of his "B" sample analysis.
"We need to take into account a lot of things, then we'll look at the rules," Tchmil said Tuesday. "He is claiming his innocence and says he can't give any explanation for his positive test. Of course we were surprised."
Katusha sports director Bart Leysen said Monday that Kolobnev met team management, then left the team hotel with police officers to be questioned at the police station, adding that they "just want to check some things with him, papers, and normally they will bring him back later."
Kolobnev returned late in the evening and spent the night in the team hotel.
"If the 'B' sample also tests positive, he will be fired and will have to pay five times his salary as a fine," the team statement said.
Tour director Christian Prudhomme expressed satisfaction with the fight against doping at the race by French anti-doping officials and the UCI.
"Fighting against doping is extremely complicated, but it's much easier when it's done together," Prudhomme said. "And here is a good example of the anti-doping authorities working together. The UCI and AFLD are working hand in hand."