Tour de France champion Floyd Landis of the United States says that he has never been involved in doping and that his high testosterone levels naturally occur because he is a professional athlete.

Landis tested positive for elevated testosterone after last week's 17th stage in the Tour de France. He told a news conference in Madrid, Spain Friday that he has never used anything illegal. He said he won the Tour through a lifetime of training, not performance enhancers.

Landis said the case was not a doping case. He also asked that he not be judged by the media and the public. He said he was equally surprised with the positive test result.

The Swiss team Phonak has suspended the American rider, pending analysis of his second urine sample. Phonak has also said it would fire Landis if his second test is positive.

The results of the second test are expected next week. If the second sample is positive, then Landis could be stripped of the Tour de France title and banned from competition.