LONDON (AP) — Former French Open finalist Sara Errani must serve a two-month doping ban after testing positive for the banned substance letrozole in a test taken in February, the International Tennis Federation said on Monday.

Errani blamed contamination from her mother’s breast cancer medication.

“I never took, in my life and during my career, any prohibited substance,” Errani said in a statement. “I am extremely disappointed but at the same time at peace with my conscience and aware I haven’t done anything wrong.”

An adjudication panel ruled that Errani’s fault was “at the lower end of the scale,” but that she should still be banned for two months from Aug. 3.

The Italian has also been retroactively disqualified from tournaments from Feb. 16 through June 7. Her only notable performance in that period was a semifinal in Rabat, Morocco, in May, plus a second-round loss at Roland Garros.

Errani’s ban will end on Oct. 2, precluding her from playing in the U.S. Open.

Errani reached the 2012 French Open final, losing to Maria Sharapova, and has completed a career grand slam in women’s doubles with Roberta Vinci.

The 98th-ranked Errani has won nine singles titles and 25 doubles titles in her WTA career. She reached a career-high singles ranking of No. 5 in 2013.

She also helped Italy to three Fed Cup titles.