Former world number one Maria Sharapova has revealed she failed a drugs test at the Australian Open.
The Russian, 28, tested positive for meldonium, a substance she has been taking since 2006 for health issues.
Sharapova, a five-time Grand Slam champion, said she was not yet aware of the sanctions she will face.
"I failed the test and take full responsibility for that," said Sharapova, who won Wimbledon as a 17-year-old in 2004.
"I had been taking this medicine for the past 10 years, but on 1 January this became a prohibited substance which I did not know.