Martial Saugy said he had one meeting with Armstrong in 2002 at the request of the International Cycling Union to talk about the tests but refuted the suggestion that he told him how to avoid detection.
"The answer to the question, is clear: no, I did not give the keys to Lance Armstrong (to avoid detection)," he said.
"It would be a paradox as my job as leader of an anti-doping laboratory. The fight against doping is our life's work.
"It's true that a meeting took place, and that's not a new fact," he added. "In the context, I think it was the right thing to do. It was not a mistake or an act of naivety as some have written.
"I've met him for only about 20 minutes in my whole life."
He added: "It's a fundamental right for the sportsmen to know the scientific basis of an analysis."
Armstrong was stripped of his seven Tour de France titles, won between 1999 and 2005, and banned for life in October following a report by the United States Anti-Doping Agency.
USADA said that Armstrong had been involved in the "most sophisticated... and successful doping programme that sport has ever seen".
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