Tennis star Maria Sharapova revealed Monday that she failed a drug test at the Australian Open.
Speaking at a news conference in Los Angeles, the five-time major champion, 28, said she had been notified by the International Tennis Federation that she had tested positive for a banned substance, meldonium.
She said she has been taking the meldonium since 2006 for health issues. But it became a banned substance this year and Sharapova said she did not check the updated banned list before taking it.
"I have been very open and honest about many things, I take great responsibility in my job," she said at the press conference. "I made a huge mistake... I let my fans down, I let the sport down that I've been playing since the age of four, that I have loved so deeply."
She has been banned from playing effective March 12 pending a review to determine what penalty she will face, authorities said.
"It is very important for you to understand that for 10 years this medicine was not on Wada's banned list and I had been legally taking that medicine for the past 10 years," said Sharapova.
"But on 1 January the rules had changed and meldonium became a prohibited substance, which I had not known."
She has been prescribed the medication by her family doctor since 2006, she said, after receiving irregular EKG results. The medication is used to treat heart problems, but has been banned as a performance-enchancing drug.
Sharapova added: "I know with this I face consequences and I don't want to end my career this way, and I really hope I get another chance to play this game."
Ahead of the press conference, there had been speculation that she would be announcing her retirement.
"I know many of you thought I'd be announcing my retirement. If I was ever going to announce my retirement, it would not be in a downtown Los Angeles hotel with a fairly ugly carpet," she said.
The Russian-born star hasn't competed since losing to Serena Williams in the Australian Open in January. She has been sidelined with an injury to her arm.
She won Wimbledon in 2004, when she was just 17. She also won the US Open in 2006, the 2008 Australian Open and the French Open titles in 2012 and 2014.