Cape Town - Athletes who tested positive for meldonium before March 1 this year could have their bans overturned after the World Anti-Doping Agency (WADA) announced it was unable to establish how quickly the drug, outlawed since Jan. 1, cleared the system.
WADA's announcement could allow five-times grand-slam tennis champion Maria Sharapova, who failed a test for meldonium in January, and other banned athletes to return to competition, Russian officials said on Wednesday.
Sharapova, the world's highest-earning sportswoman, was among 40 Russians who failed dopes tests for meldonium after it was added to WADA's list of banned substances in January.
WADA said there was "currently a lack of clear scientific information on excretion times. As a result it is difficult to know whether an athlete may have taken the substance before or after January 1, when it became illegal.
"In these circumstances, WADA considers that there may be grounds for no fault or negligence on the part of the athlete," it said in a statement sent to anti-doping agencies and sports federations, adding that the presence of less than one microgram of meldonium in the samples was acceptable.
Sharapova, who said she had been taking meldonium for more than a decade because of health problems, was banned by the International Tennis Federation (ITF) on March 12 after announcing she had failed a test at the Australian Open in Melbourne.