Paris - America's Varvara Lepchenko refused to comment Tuesday on claims that she served a 'silent ban' after testing positive for meldonium, the drug which has put Maria Sharapova's career on hold.
The Uzbekistan-born world number 64 didn't play on the WTA Tour from February to May.
The reason, according to allegations made by Russian physio Anatoly Glebov, was that she had tested positive for 1mg of meldonium.
However, as that is below the limit set by the World Anti-Doping Agency (WADA) she was allowed to return to competition in Rome earlier this month.
Eight times Lepchenko was asked to address the allegations, but eight times she refused after losing to Russia's Ekaterina Makarova at the French Open on Tuesday.
"At the moment I have no comment on any of this. I'm here just to answer tennis questions. If you have any questions about my match, I would gladly answer them," she said.
"But otherwise, I just have no comments."
Sharapova was suspended in March after she revealed she had tested positive for meldonium at the Australian Open in January.