Maria Sharapova has revealed she failed a drugs test at the Australian Open.
The Russian world number seven, a five-time grand-slam champion, announced the news in a media conference on Tuesday.
"Thank you for being here on such short notice. I wanted to let you know that a few days ago I received a letter from the ITF [International Tennis Federation] that I had failed a drugs test at the Australian Open," Sharapova said.
"I have to take full responsibility, because it's my body and it's what I put into my body. I can't blame anyone but myself.
"At the end of the day, everything you do is about you.
"I received a letter on December 22 from WADA, an email with the changes happening for next year and a link where you can press a button to check the prohibited items for 2016 and I did not look at that list.
"I do not [know what the consequences will be]. This is very new to me. I just received the letter a few days ago and I will be working with the ITF.
"I do not know yet [when I can play again].
"I was first given the substance back in 2006 - I had several health issues going on at the time, I was getting sick very often ... that was one of the medications, along with several others, that I had received.
"I'm still working through my injury and that is the reason I withdrew from Palm Springs.
"It made me healthy and that's why I continued to take it."
Speculation had been rife that the 28-year-old was to announce her retirement from tennis after calling the conference for a "major announcement".