Tour de France [Images] winner Floyd Landis denied on Thursday taking performance-enhancing drugs during the race and said he would fight to clear his name after testing positive for the male sex hormone testosterone.

"I don't know what the explanation for it is, whether it was a mistake or whether it's an occurrence from some other circumstances that go on in the race or something I did," he told reporters in a teleconference call.

"But it was not from an exogenous outside source of testosterone."

When asked by reporters if he had taken any banned substances to boost his performance during the race, Landis replied: "No".

If Landis's B sample confirms the result, the 30-year-old American is certain to be stripped of his victory, becoming the first Tour winner to be disqualified for doping.

Spain's Oscar Pereiro, who finished second in the overall standings, would be declared the winner if Landis is disqualified.

"Most of the public has an idea about cycling because of the way things have gone on in the past. I know a lot of people are going to think I'm guilty before I have a chance to defend myself.

"All I'm asking for is that I be given what everybody in America is accustomed to -- innocent until proven guilty, rather than the way cycling is normally treated," he added.

STIGMA

Landis said he was determined to clear himself of the doping charges, but was resigned to the fact the stigma of the positive test might never leave him.

"Unfortunately, I don't think this is ever going to go away no matter what happens next," said Landis, who was speaking from Europe but would not be specific about his exact location.

"I think there's a possibility I can clear my name. That's what I want to do, that's my objective now. But regardless of whether that happens or not I don't know if this will ever really go away."

Landis provided the positive sample after a brilliant ride in the 17th stage, a grueling ride to Morzine in the French Alps, a day after a disastrous showing had appeared to ruin his chances of victory.

The American said that the night before the 17th stage he and his Phonak teammates had been depressed and had drunk beer and whiskey in their hotel room.