Seven-time Tour de France winner Lance Armstrong has insisted on his innocence despite a report in French newspaper L'Equipe that he used the blood-boosting drug EPO in 1999.

"I will simply restate what I have said many times: I have never taken performance-enhancing drugs," the 33-year-old American said in a statement on his personal website.

His remarks came after L'Equipe reported on Tuesday that "indisputable" traces of EPO (erythropoietin) were found in six of Armstrong's urine samples collected on the 1999 Tour de France when he made his cycling comeback after defeating testicular cancer.

L'Equipe published a results sheet from the lab which appeared to show six figures revealing traces of EPO. Documents from the French cycling federation were also published showing exactly the same figures under Armstrong's name.

L'Equipe had frequently raised questions about how Armstrong could have made his spectacular comeback from cancer without using performance enhancers.

EPO, a drug that increases the level of red blood cells and endurance, was not detectable in 1999, but samples from the 1999 Tour were kept and have been recently retested by the anti-doping laboratory in Chatenay-Malabry outside Paris.

The Chatenay-Malabry lab said in a statement that the samples they tested did not have names attached and they could not confirm if any of the samples were Armstrong's.

The lab added that all test results had been sent to WADA, the agency in charge of the fight against doping in world sport.

Armstrong retired from cycling after winning his seventh straight Tour de France last month.

Source: Xinhua