The director of a Swiss drug-testing laboratory has agreed to provide information to investigators seeking to corroborate accusations by two former teammates of Lance Armstrong that the seven-time Tour de France champion used performance-enhancing drugs and conspired to cover up a positive drug test from the Tour de Suisse in 2001.

Armstrong’s representatives contend that nothing the lab director could provide would damage the case of their client, who has repeatedly denied using banned drugs and challenged the credibility of his accusers.

Martial Saugy, the Lausanne-based lab director, sought out anti-doping authorities last year shortly after Floyd Landis became the first cyclist to accuse Armstrong publicly, according to World Anti-Doping Agency Director General David Howman. In September, Saugy met with Jeff Novitzky, a special agent with the Food and Drug Administration who has led the U.S. government’s probe of Armstrong, at WADA’s Montreal headquarters. FBI and U.S. Anti-Doping Agency officials also attended the meeting.

Last July, Saugy met in Moscow with USADA chief executive Travis Tygart, according to an April 14 letter that USADA sent to Saugy.

As a follow-up to the meetings, Saugy agreed to provide by May 2 information about all “suspicious” results from EPO analysis during the 2001 Tour de Suisse, as well as the particulars of discussions related to EPO testing that occurred during a meeting with Armstrong or his team manager Johan Bruyneel, according to the April letter.

Authorities want to determine whether any of Armstrong’s samples raised reg flags, whether he or his representatives were improperly tipped off to testing results, and whether international cycling officials acted appropriately on information they received from the Swiss lab.

Saugy told the German-language newspaper Neue Züricher Zeitung in Friday’s editions that there were four “suspicious” tests during the Tour de Suisse but that he didn’t know whether any belonged to Armstrong and did not believe any cover-up had occurred. He also confirmed meeting with Armstrong and Bruyneel during a later trip to collect blood, and explaining to them how the EPO test worked, but said the meeting was not to discuss any results.

Saugy said the only body to whom he reported the four suspicious results from the race — and which would know the athlete or athletes who produced the samples — was the International Cycling Union (UCI).

The existence of the letter was first reported by “60 Minutes” in an episode that aired Sunday. In the report, Tyler Hamilton became the second former teammate of Armstrong to allege that he saw Armstrong use drugs. He also said Armstrong told him he tested positive at the 2001 Tour de Suisse and that he and officials from the UCI figured out a way to make it go away.

Armstrong has repeatedly said he has taken more than 500 tests without a positive result. Armstrong’s attorney Tim Herman added in a statement that “neither Armstrong or Bruyneel have any recollection of meeting [Saugy] for any purpose at any time,” and “Armstrong was never informed by anyone in 2001 or any other time about either a positive or ‘suspicious’ test” from the Tour de Suisse.”

But after Landis made his allegation last summer, Saugy approached Howman during meetings in Lausanne, expressing concern about a “suspicious result” he had discovered during a doping analysis years previously, Howman said.

“What he did was quite professional and quite proper,” Howman said. “I stopped the conversation. I put him in touch with the right people.”

In a statement, Tygart said: “We cannot comment on the substance of an ongoing investigation. We have confirmed that we are actively investigating issues in the sport of cycling, and our duty is to fairly and thoroughly pursue any and all reliable evidence of doping.”

Howman said he did not have direct knowledge of Saugy’s claims because he did not participate in interviews with him, but any meeting between any lab director and athlete would be “unwise and inappropriate and can threaten the whole foundation of a proper [anti-doping] process.”

Howman also explained that a “suspicious” test would be one that might alert drug-testing authorities to possible drug use, but probably would not be so far out of bounds that it could be considered a “positive.” Because 2001 was the first year of testing for EPO, Howman noted that all lab directors likely would have been very cautious about reporting tests as positive.

“It’s not ‘positive’ unless it’s recorded,” Howman said. ”There was no positive test, because nothing was reported as positive. It was a suspicious result.”

Saugy told the newspaper that the results could not have been interpreted as positive at the time, and the urine samples were not saved.

Howman said the appropriate course of action in the case of a suspicious result would be for the lab director to alert the authority conducting the tests — in this case UCI — about the suspicious sample so that follow-up testing could be conducted on the athlete in question.

Because anti-doping lab directors know samples only by numbers, the agency conducting the testing would have to determine the name of the athlete and assign additional testing to the athlete.

It is not clear whether that process occurred. Armstrong’s representatives say he was tested at least five times during the 2001 Tour de Suisse.

They further point out that samples from Armstrong and his U.S. Postal Service team from the 2000 Tour de France that had been frozen after the race had been tested for EPO when the test came online in 2001. All were declared negative.

Donations of $125,000 from Armstrong to UCI since 2002 also have raised eyebrows, providing fuel for those who allege Armstrong engineered a doping cover-up. UCI and Armstrong have said the money went to purchase better anti-doping equipment.

Landis characterized the transaction as a bribe.

“It would be impossible to cover up a test when there are multiple independent agencies responsible for testing,” Herman said in the statement.