Floyd Landis tested positive for high levels of testosterone during Tour de France.

Floyd Landis’ racing team, Phonak, received notification from cycling’s world governing body (UCI) that the Tour winner had tested positive for “an unusual level of testosterone/epitestosterone.”

According to the UCI, based in Aigle, Switzerland, Landis’ test results after the 17th stage produced a questionable sample. A test of his backup sample will be requested and the results could determine the fate of a man lauded for his courage and determination.

Entering the 17th stage Landis had been written off as a potential champion. Over eight minutes behind the leader and facing a rigorous Alps climb Landis accomplished what has been dubbed "the best performance in the modern history of the Tour" by race director Jean-Marie Leblanc.

Phonak has suspended their number one rider, and awaits an analysis of his backup sample “to prove either that this result is coming from a natural process or that this is resulting from a mistake."

"The team management and the rider were both totally surprised of this physiological result," the Phonak statement said. Despite the surprise, the team is ready to fire the American if the second test confirms the doping.

The Tour de France was already in critical condition after nine riders had been sent home prior to the race for allegations of doping, among them pre-race favorites Jan Ullrich and Ivan Basso.