Italy's Sara Errani has been suspended for two months after failing a doping test, the International Tennis Federation announced on Monday.
The 30-year-old former world number five, who reached the French Open final in 2012, tested positive for the banned substance letrozole in an out-of-competition test in February.
Letrozole is used in the treatment of breast cancer, but can also be used as a masking agent.
"An Independent Tribunal ... has found that Sara Errani committed an Anti-Doping Rule Violation ... and, as a consequence, has disqualified the affected results and imposed a period of ineligibility of two months, commencing on 3 August 2017," the ITF said in a statement.
Errani's results between February and June have been wiped and she has forfeited all prize money and ranking points that she accumulated during that period.
Errani reached her highest world ranking of five in 2013, but has since slipped to number 98.
In a statement posted on her Twitter page, she wrote: "I never took, in my life and during my career, any prohibited substance.
"However, this substance (letrozole) is present in Femara, a medicine my mother has been using daily since 2012 for therapeutic purpose, further to a surgery for breast cancer, and therefore is present in the house where I am currently living."
Errani said she was likely to have consumed the drug via "accidental food contamination".
She said she was "very frustrated" and "extremely disappointed" by the outcome of the ITF tribunal, but was nonetheless "at peace with my conscience and aware I haven't done anything wrong".
Italian rower Niccolo Mornati, a four-time medallist at the World Championships, tested positive in 2016 for the same substance.