A French newspaper, Le Monde, published a report in Friday's editions claiming that Armstrong admitted to doping three years before the first of his seven Tour wins in 1999.
Armstrong's attorney strongly denied the claim, and gave The Associated Press a copy of an affidavit from one of the lead doctors who treated Armstrong's testicular cancer.
The Texan, retired from cycling since his seventh consecutive Tour victory last year, has consistently insisted that he never took banned drugs to enhance his performances and he was never sanctioned for any doping offense during his career.
Le Monde, however, said former Armstrong teammate Frankie Andreu, and his wife, Betsy, recently testified under oath to a Dallas court that Armstrong admitted in 1996 to having taken the blood-boosting hormone EPO and other banned substances. The paper said Frankie Andreu used to be best friends with Armstrong.
Le Monde claimed that Armstrong's alleged admission was made Oct. 28, 1996, to a doctor who was treating him for cancer. Betsy Andreu testified that the doctor asked Armstrong whether he had ever taken doping products, and that the cyclist replied "yes," according to Le Monde. The newspaper said she and her husband were with Armstrong on that day.
"He asks which ones. And Lance replies, 'EPO, growth hormones, cortisone, steroids, testosterone,"' it quoted her as telling the court in January. The newspaper said it obtained a copy of her testimony but did not say how.
Armstrong's attorney, Tim Herman, Texas denied the Andreus' claim, calling it "absurd."
In a sworn affidavit, Dr. Craig Nichols said he and other medical personnel visited with Armstrong that day about his medical history before he started chemotherapy.
"Lance Armstrong never admitted, suggested or indicated that he has ever taken performance-enhancing drugs. Had this been disclosed to me, I would have recorded it, or been aware of it, as a pertinent aspect of Lance Armstrong's past medical history as I always do," Nichols said.
"Had I been present at any such 'confession,' I would most certainly have vividly recalled the fact," Nichols said. "I would have recorded such a confession as a matter of form, as indeed, would have my colleagues. None was recorded."
The court was hearing a case brought by Armstrong against a company that withheld a bonus for his 2004 Tour win because a book alleged that he used performance-enhancers.
After hearing the evidence, including the Andreus' testimony, the three-member arbitration panel ruled against the company and ordered it to pay Armstrong.
Le Monde said that Frankie Andreu, who raced with Armstrong for the first two of his Tour wins in 1999 and 2000, gave a similar deposition last October, also alleging that Armstrong told the doctor that he used EPO, testosterone, growth hormone and cortisone.
The newspaper said the Andreus' account was denied by a third person, Stephanie McIlvain, a friend of Armstrong's who supposedly was also at the session with the doctor. She testified that she did not hear Armstrong make such an admission, Le Monde said.
"There were probably 10 people in the room. Betsy was apparently the only one that recalls this alleged incident," Herman said.
In his own defense, Armstrong said in a November deposition to the court that no doctor had asked him whether he had used doping products, according to the newspaper. It said Armstrong also told the court that Betsy Andreu hated him and that Frankie Andreu had gone along with her account to offer her support.
Herman said he has 280 pages of medical records from Indiana University Medical Center, where Armstrong was treated for his cancer, which had spread to his brain, that refute the allegations.
Armstrong's doctors repeatedly asked him during his treatment about substances he may have taken and Armstrong answered only that he occasionally drank beer, Herman said.