Tour director Jean-Marie Leblanc's comments appeared in the French sports daily L'Equipe on Wednesday, a day after the newspaper reported that six urine samples provided by Armstrong during the '99 Tour tested positive for the red blood cell-booster EPO.
``For the first time and these are no longer rumors, or insinuations, these are proven scientific facts someone has shown me that in 1999, Armstrong had a banned substance called EPO in his body,'' Leblanc told L'Equipe.
``The ball is now in his court. Why, how, by whom? He owes explanations to us and to everyone who follows the tour. Today, what L'Equipe revealed shows me that I was fooled. We were all fooled.''
On Tuesday, Leblanc called the latest accusations against Armstrong shocking and troubling.
Armstrong, a frequent target of L'Equipe, vehemently denied the allegations Tuesday, calling the article ``tabloid journalism.''
``I will simply restate what I have said many times: I have never taken performance-enhancing drugs,'' he said on his Web site.
Armstrong, who retired from professional cycling after winning the Tour a month ago, was not immediately available for comment regarding Leblanc's latest remarks.
EPO, formally known as erythropoietin, was on the list of banned substances at the time Armstrong won the first of his seven Tour's, but there was no effective test then to detect it.
The allegations surfaced six years later because EPO tests on the 1999 samples were carried out only last year when scientists at a lab outside Paris used them for research to perfect EPO testing. The national anti-doping laboratory in Chatenay-Malabry said it promised to hand its finding to the World Anti-Doping Agency, provided it was never used to penalize riders.
Five-time cycling champion Miguel Indurain said he couldn't understand why scientists would use samples from the 1999 Tour for their tests.
``That seems bizarre, and I don't know who would have the authorization to do it,'' he told L'Equipe. ``I don't even know if it's legal to keep these samples.''
L'Equipe's investigation was based on the second set of two samples used in doping tests. The first set were used in 1999 for analysis at the time. Without those samples, any disciplinary action against Armstrong would be impossible, French Sports Minister Jean-Francois Lamour said.
Lamour said he had doubts about L'Equipe's report because he had not seen the originals of some of the documents that appeared in the paper.
``I do not confirm it,'' he told RTL radio. But he added: ``If what L'Equipe says is true, I can tell you that it's a serious blow for cycling.''
The International Cycling Union did not begin using a urine test for EPO until 2001, though it was banned in 1990. For years, it had been impossible to detect the drug, which builds endurance by boosting the production of oxygen-rich red blood cells.
Jacques de Ceaurriz, the head of France's anti-doping laboratory, which developed the EPO urine test, told Europe-1 radio that at least 15 urine samples from the 1999 Tour had tested positive for EPO.
Separately, the lab said it could not confirm that the positive results were Armstrong's. It noted that the samples were anonymous, bearing only a six-digit number to identify the rider, and could not be matched with the name of any one cyclist.
However, L'Equipe said it was able to make the match.
On one side of a page Tuesday, it showed what it claimed were the results of EPO tests from anonymous riders used for lab research. On the other, it showed Armstrong's medical certificates, signed by doctors and riders after doping tests and bearing the same identifying number printed on the results.
L'Equipe is owned by the Amaury Group whose subsidiary, Amaury Sport Organization, organizes the Tour de France and other sporting events. The paper often questioned Armstrong's clean record and frequently took jabs at him portraying him as too arrogant, too corporate and too good to be real.
``Never to such an extent, probably, has the departure of a champion been welcomed with such widespread relief,'' the paper griped the day after Armstrong won his seventh straight Tour win and retired from cycling.
Leblanc suggested that in the future, urine samples could be stashed away for future testing as detection methods improve another possible weapon in the fight against doping.
``We're so tired of doping that all means are good as long as they are morally acceptable,'' he told L'Equipe