AIGLE, Switzerland -- Russian track cyclist Valery Kaykov has been suspended after testing positive for a black-market drug that the World Anti-Doping Agency issued a health warning about last month.
The International Cycling Union says Kaykov, a European Championships silver medalist last year, tested positive in an out-of-competition sample for the substance WADA called "GW501516."
The UCI says his sample was given on March 17, four days before WADA urged athletes not to use the endurance-boosting substance that had toxic side effects in pre-clinical studies.
Kaykov is provisionally suspended from competition while the Russian cycling federation prosecutes a disciplinary case.
The UCI says Kaykov can request to attend the analysis of his backup sample. The original test was done by the WADA-accredited laboratory in Cologne, Germany.