Five-time Grand Slam champion Maria Sharapova announced at a news conference that she failed a drug test at the Australian Open. The current world No. 7 said she was notified by the International Tennis Federation several days ago. The Tennis Anti-Doping Program confirmed that she will be “provisionally suspended” starting on March 12, “pending the determination of the case.”

The drug is called meldonium, though Sharapova said she had been using it under the name of mildronate and was unaware of both the different name and the fact it is on the World Anti-Doping Agency’s banned list until she received a letter notifying her of the positive test 10 days ago.

Sharapova claimed she was prescribed meldonium by her doctor in 2006 to deal with health issues such as an irregular heartbeat and a history of diabetes in her family. But the substance was added to the banned list in January of this year because Wada said there was “evidence of its use by athletes with the intention of enhancing performance”.

About Meldonium

• Meldonium was developed years ago in Latvia to treat patients with heart conditions brought on by a lack of oxygen in their blood.
• It has become popular with athletes who use the oxygen-enhancers to improve endurance, especially when working out.
• Last year Wada announced that it was carefully studying the drug, allowing athletes to take it with the warning that it could soon be banned.
• A few months into that study Wada said meldonium was being moved to 2016’s banned list.

Sharapova has been the highest-earning female athlete in the world in each of the past 11 years, according to the Forbes list.