The French lab conducting the tests sent a letter to cycling's world governing body noting Rasmussen's samples showed signs of Dynepo, an EPO-like substance made from human cells, L'Equipe said.

But Pierre Bordry, leader of France's anti-doping agency, told The Associated Press the results — if reported accurately — could not be treated as a positive test, because Dynepo is not banned under World Anti-Doping Agency regulations.

"EPO as a synthetic product is forbidden," he said. "EPO made from a biological element ... does not appear in the analysis the same way as EPO."

"The World Anti-Doping Agency must absolutely get laboratory standards modified so that we can recognize (this kind of EPO) as forbidden," Bordry said.

Asked about the case, International Cycling Union spokesman Enrico Carpani said, "There is no positive result. Not at all. ... Nevertheless, it can happen that a lab gives comments and additional information on a negative case, assuming it will help us in our work."

Carpani said it was up to WADA to determine the rules when a result is positive.

Bordry said about 10 cases of use of EPO-related substances by track and field athletes were reported to his agency this spring.

Rasmussen was pulled out of the Tour by his Dutch team Rabobank for allegedly lying about his whereabouts to avoid out-of-competition doping tests before the Tour. He was leading the Tour when he was expelled.

Bordry's agency could not confirm the L'Equipe report as it is not regularly informed of such test results, according to WADA rules.

"If the information (in L'Equipe) is correct, the case will be passed on to UCI," Jens Evald, chairman of Anti-Doping Denmark, said in a TV interview.