Tennis star Maria Sharapova has revealed that she failed a drug test at the Australian Open due to the presence of meldonium, a drug used to treat diabetes and low magnesium.

The five-time grand slam champion, who is also the highest-paid woman in sport, said she had been taking the substance for the last ten years because of health issues.

"I made a huge mistake. I let my fans down and I let the sport down. I take full responsibility for it," Sharapova said at a news conference.

The International Tennis Federation (ITF) has said Sharapova, 28, will be provisionally suspended starting March 12.

"I know that with this I face consequences and I don't want to end my career this way. I really hope that I will be given another chance to play this game," the Russian said in Los Angeles.

Usually, under the anti-doping programme, the ITF imposes a four-year suspension on a player testing positive.

The tennis star said her family doctor prescribed the drug, also known as mildronate. This was prescribed after she frequently became sick and had a magnesium deficiency and a family history of diabetes.