MELBOURNE, AUSTRALIA - JANUARY 20: Maria Sharapova of Russia plays a forehand in her second round match against Aliaksandra Sasnovich of Belarus during day three of the 2016 Australian Open at Melbourne Park on January 20, 2016 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)

Tennis star Maria Sharapova is facing a two-year ban after failing a drugs test at this year's Australian Open.

Sharapova tested positive to the banned substance Mildronate, also known as meldonium, which the 28-year-old says she uses to counter a magnesium deficiency  and a family history of diabetes.

The substance, which she has been taking since 2006, was added to WADA's banned list on January 1 this year. All players were informed of the updated WADA banned list for 2016 in December, but Sharapova admitted she "didn't read" the letter.

Meldonium has been found to increase blood flow which improves exercise capacity in athletes.

Sharapova said she takes "full responsibility" for failing the test.

“I have no one to blame but the end of the day, everything that you do is about you,” Sharapova said.

“I have been very open and honest about many things, I take great responsibility in my job ... I made a huge mistake.

“I received an email from WADA ... with a link where you could see the prohibited items for 2016. And I did not look at that list.

“I do not (know the consequences). This is very new to me. I just received a letter a few days ago and I will be working with the ITF.

"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.

"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.

"I was getting sick very often and I had a deficiency in magnesium and a family history of diabetes, and there were signs of diabetes. That is one of the medications, along with others, that I received."

Sharapova will be provisionally suspended from March 12 and could face a two-year ban.