Floyd Landis's Tour de France victory is under scrutiny and the sport of cycling is once again under the microscope after news that the American cyclist tested positive for high testosterone levels.

Phonak, Landis's racing team, announced Thursday that the rider's urine sample showed "an unusual level of testosterone/epitestosterone" when he was tested after his title-saving performance in Stage 17 of the race a week ago.

Phonak has suspended Landis pending results of the backup B sample of his drug test.It's not known when the results of Landis's backup sample will be examined, but Phonak said it would fire him if the results are positive.

Even if his B sampleturns out to be clean, Landis admitted during a Thursday teleconference that he won't be able to escape the cloud of suspicion following him.

"Unfortunately, I don't think it's ever going to go away no matter what happens next," said Landis. "It appears as though this is a bigger story than winning the Tour, so that's going to be hard to go away."

The news comes the day after the cycling's world governing body said an unnamed cyclist in this year's race tested positive for doping.

"I think there's a good possibility I'll clear my name," said Landis. "Regardless of whether this happens or not, I don't know if this will ever go away."

In an interview with Sports Illustrated's website, Landis denied taking performance-enhancing drugs to win the Tour de France.

"Unfortunately, I don't think it's ever going to go away no matter what happens next" -Floyd Landis

Landis told cnnsi.com that elevated levels of testosterone are common among cyclists and that he is retaining the services of Spanish doctor Luis Hernandez to help prove his innocence.

"In hundreds of cases, no one's ever lost one," Landis told journalist Austin Murphy.

Landis also suggested that an oral dose of thyroid hormone he's been taking to help a thyroid condition could be to blame for the positive result. He also said cortisone shots for his degenerative hip condition might have affected the test's outcome.

"All I'm asking for,"Landiscontinued, "is that I be given a chance to prove that I'm innocent. Cycling has a traditional way of trying people in the court of public opinion before they get a chance to do anything else.

I would like to be presumed innocent until proven guilty — since that's the way we do things in America."

Asked repeatedly what might have tripped his positive test, Landis refused to lay blame on anything in particular.

"As to what actually caused it on that particular day, I can only speculate," he said.

Landis said he was still in Europe, but declined to say exactly where. "Not to be elusive, I have to figure out a way to get to the airport and get home."

Miraculous win shrouded in controversy

The 2006 Tour de France wrapped up Sunday with Landis capturing the three-week cycling race after the final stage through central Paris and down the city's famed Champs Elysée.

Phonak was notified by the Union Cycliste Internationale (UCI) of Landis's elevated testosterone-epitestosterone ratio in a doping test taken after the 17th stage.

It was during that Alpine stage that Landis launched his improbable comeback. One day earlier, Landis faltered while climbing to La Toussuire in the final kilometres of Stage 16.

He ended up losing the stage by 10 minutes and fell from first to 11th place overall, ending up eight minutes behind leader Oscar Pereiro of Spain. At that point, the American's quest for the Tour crown appeared to be over.

But in one of the greatest comebacks in the history of the Tour, Landis embarked on a 120-kilometre solo breakaway to win Stage 17 by a whopping six minutes. That remarkable effort pushed him up to third in the overall standings as he whittled Pereiro's lead to a mere 30 seconds.

Landis then finished third in Stage 19, a 57-kilometre individual time trial, to leapfrog Pereiro and reclaim the yellow jersey as overall leader, setting the stage for Sunday's procession into Paris, where he was crowned champion, succeeding seven-time winner Lance Armstrong.

Disheartened by positive test

Pereiro, who stands to become Tour de France champion if Landis is stripped of the title, was in no mood to celebrate Thursday.

"Should I win the Tour now it would feel like an academic victory," the Spaniard told the Associated Press. "The way to celebrate a win is in Paris, otherwise it's just a bureaucratic win."

Under World Anti-Doping Agency regulations, a ratio of testosterone to epitestosterone greater than 4:1 is considered a positive result and subject to investigation. That mark was recently lowered from 6:1. The natural ratio of testosterone to epitestosterone in humans is usually between 1:1 and 2:1.

"It hurts a lot, it hurts for Landis and for the sport," said Pereiro. "The sport had just been recovering after what happened before the Tour began, and this just hurts it when it was beginning to get over the past."

When news broke Wednesday that an unidentified rider had tested positive, UCI president Pat McQuaid wouldn't comment on who the rider was, saying only he was discouraged by the news.

"I will say that I am extremely angry and feel very let down by this," McQuaid told the Times Online. "The credibility of the sport is at stake. The rider, his federation and his team have been informed of the decision."

Suspicions arose that Landis had tested positive after he failed to show up for a one-day race in Denmark on Thursday. He also missed a race in the Netherlands on Wednesday.

Tour marred by doping scandal

Landis's positive test is the latest embarrassment for cycling's biggest race.

The opening of the Tour was rocked by a doping scandal, with several of the sport's top riders barred from the race after being implicated in a major investigation in Spain.

Among those banned from the race were Jan Ullrich, the 1997 Tour de France champion and five-time runner-up, his T-Mobile teammate Oscar Sevilla and the team's sporting director, Rudy Pevenage.

Ivan Basso, who placed 11th in 2002, seventh in 2003, third in 2004 and second in 2005, was also barred from this year's race, as were Spanish racers Francisco Mancebo and Joseba Beloki. Basso was a member of the CSC team.

Ullrich and Basso's names turned up on a list of 56 cyclists who allegedly had contact with Spanish doctor Eufemiano Fuentes. Cyclists allegedly went to his Madrid clinic to have blood extracted for doping or to collect performance-enhancing drugs.

Nearly 100 bags of frozen blood and equipment for treating blood were found at the clinic, along with documents on doping procedures performed on cyclists.

With files from the Associated Press