The 29-year-old Spaniard has been provisionally suspended by cycling’s governing body after returning a positive test in an out-of-competition control June 26, eight days before the Tour began and nearly a month before he won its 16th stage.
It is first doping case of the 2009 Tour.
“I know that I have not taken any prohibited substance and I say so emphatically,” Astarloza said at a news conference Tuesday. “Whatever it takes, I’m going to discover how this supposed positive result happened.
“I’ve never been under suspicion, neither by the UCI nor by my team, and my biological parameters have always been correct.”
He said there is evidence that casts doubt on the credibility of the analysis but declined to comment further “until the ideal moment.”
Astarloza said that when he was told of his positive test in a telephone call from a UCI inspector last Friday he thought it was a joke and called Euskaltel-Euskadi team director Igor Gonzalez de Galdeano and doctor Guillermo Cuesta to try and clear up the situation.
Astarloza said he has lost faith in the system, even if a second analysis proves his innocence.
“The damage has been done,” he said. “I’m innocent and I’m being accused of something I haven’t done. This is a very serious situation.”
Astarloza won the 98.8-mile 16th stage, a trek through the Swiss, Italian and French Alps, on July 21.