Five-time Grand Slam champion Maria Sharapova revealed on Tuesday (March 8) that she had failed a drugs test at this year's Australian Open.
The 28-year-old tennis star admitted that she had been taking meldonium the past 10 years, the drug was only added into the World Anti-Doping Agency's (Wada) list for banned substances on Jan 1, 2016.
Sharapova denied that she has been doping, claiming that she was unaware that meldonium had been added to the list of prohibited substances. However, she has taken full responsibility for failing the test, adding that she has made a "huge mistake".
Here's more about the drug.
What is meldonium?
It is an anti-ischemic drug that helps improve circulation to parts of the body, particularly the brain.
It is also used to treat heart conditions such as angina and myocardial infarction, where there is a restricted blood flow to the heart.
It is currently manufactured and marketed by a pharmaceutical company called Grindeks, which is based in Latvia.
Why was Sharapova taking it?
Sharapova said that she was falling sick regularly. She also had a magnesium deficiency and a family history of diabetes.
She was prescribed the drug in 2006 and has been taking it ever since to cope with her health issues. Prior to the drug's ban in Jan 1, 2016, she had been legally taking the medicine. She has only broken the rules during this year's Australian open.
Is it performance enhancing?
Meldonium is also known as Mildronate which improves the user's stamina, endurance and rate of recovery.
Have other athletes been banned for taking meldonium?
Meldonium abuse is not widespread among athletes. There have only been a few positive tests over the past month.
Russian cyclist Eduard Vorganov, Russian figure skater and Olympic gold medallist Ekaterina Bobrova, Ethiopia-born athletes Endeshaw Negesse and Abeba Aregawi and Ukraine biathletes Olga Abramova and Artem Tyshchenko have all tested positive for meldonium so far.
Sources: The Guardian, ABC