American Floyd Landis is likely to lose his Tour de France title after a second drugs sample on Saturday confirmed a positive test for excessive amounts of the male sex hormone testosterone.

Landis tested positive after his victory on the 17th stage of the Tour on July 20.

The Phonak rider will probably be stripped of his Tour de France title and faces a two-year ban from the sport. He would also lose his 450,000 euro ($575,700) prize money.

He also faces the sack from his Swiss team, who could not be reached immediately for comment.

"The UCI communicates that the analysis of the sample B of Floyd Landis's urine has confirmed the result of an adverse analytical finding notified by the anti-doping laboratory of Paris on 26th July, following the analysis of the sample A," UCI said in a statement.

"In accordance to the anti-doping rules, the Anti-Doping Commission of the UCI will request that the USA Cycling Federation open a disciplinary procedure against the rider."

Spaniard Oscar Pereiro Sio, who finished second 57 seconds adrift of Landis in the overall standings, is now likely to be declared the winner of the race.

He would then become the first Spaniard to win the Tour since Miguel Indurain's last victory in 1995.

According to the good behaviour charter of the teams, Landis would not be allowed into a Pro Tour team for a further two years.

It would be the first time in the history of the sport's biggest event that a Tour winner has been disqualified for doping.

Landis, 30, tested positive for testosterone after an astounding comeback in the last mountain stage of the world's greatest cycling race, just a day after a very poor performance which all but knocked him out of contention.

The American has denied any wrongdoing and said his body naturally produced high levels of testosterone.

Landis now has 10 days to respond to the documents that are provided, according to USADA rules.

Those documents, Landis's response and any documents USADA would provide will go to a review panel some time after the 10 days.

The review panel will make a recommendation whether or not there is a case. USADA, based on that recommendation, will then decide whether to charge Landis.

If USADA does charge the Phonak rider, he would have an opportunity to contest that decision and the recommended sanction before a U.S panel of judges.

Landis's lawyers could then take the matter to the Court of Arbitration for Sport (CAS) and a long procedure would begin.