The International Cycling Union, the sport's world governing body, has appointed a special expert to investigate doping allegations against seven-time Tour de France winner Lance Armstrong of the United States.

Dutch lawyer Emile Vrijman and his firm will look into a French laboratory's analysis of urine samples from the 1999 Tour. Vrijman is the former director of the Netherlands' National Anti-Doping Agency (NeCeDo).

The French newspaper L'Equipe claimed that six of Armstrong's 17 samples from that race tested positive for drugs. The newspaper cited evidence taken from frozen "B" samples given at the tour, and two tests are needed for a positive result. The "A" samples were used and destroyed in 1999, making a second test impossible.

Armstrong has vehemently denied ever using drugs. The 34-year-old American cyclist has questioned the validity of tests on samples frozen six years ago, how the samples were handled since then, and how he could defend himself when the confirming evidence no longer exists.

Some information for this report provided by AFP.