The World Anti-Doping Agency (WADA) has issued a warning to athletes about the health risks associated with a banned performance-enhancing drug.
GW501516 was withdrawn from research in the pharmaceutical industry after serious toxicities were reported in studies, but it remains available on the black market.
"The side effect of this chemical compound is so serious that WADA is taking the rare step of warning 'cheats' to ensure that there is complete awareness of the possible health risks to athletes who succumb to the temptation of using GW501516 for performance enhancement," said WADA in a statement.
The governing body revealed that several athletes have already tested positive for the drug, but did not disclose their identities.