Five-time Grand Slam tennis champion Maria Sharapova said Monday she failed a dope test at the Australian Open, and isn't sure what punishment she'll face for her "huge mistake."

The former world number one from Russia said a change in the World Anti-Doping Agency's banned list for 2016 led to an inadvertent violation, for which she will be "provisionally suspended" by the International Tennis Federation.

Sharapova tested positive for Meldonium, a drug she said she had been taking since 2006 but was only added to the banned list this year.

"I did fail the test and I take full responsibility," Sharapova said at a press conference at a Los Angeles hotel. "I made a huge mistake. I let my fans down. I let my sport down that I've been playing since the age of four that I love so deeply," she added , her voice wavering.
"I know that with this, I face consequences and I don't want to end my career this way -- and I really hope I will be given another chance to play this game."

The ITF confirmed in a statement that Sharapova had tested positive on January 26 and had accepted the finding when she was notified on March 2.

"Ms Sharapova will be provisionally suspended with effect from 12 March, pending determination of the case," the ITF said.

Sharapova said she was cooperating with the ITF and did not yet know the extent of the sanctions she would face.

Her attorney, John Haggerty, said the positive test could carry a ban of up to four years, but that mitigating circumstances could see a lesser penalty.

Shamil Tarpishchev, head of the Russian tennis federation, told the TASS news agency he believed Sharapova would still have a chance to play at the Rio Olympics in August.

"I am saddened to hear this news," WTA chief executive Steve Simon said in a statement. "Maria is a leader and I have always known her to be a woman of great integrity. Nevertheless, as Maria acknowledged, it is a player's responsibility to know what they put in their body and if it is permissible."

Australian tennis officials also said they were surprised to learn that Sharapova tested positive in Melbourne.

Sharapova said she originally began taking Meldonium for a variety of symptoms, including a tendency to become ill often, an irregular EKG heart test and a family history of diabetes.

A string of sports figures have tested positive for it this year, including Russian ice dancer Ekaterina Bobrova.

SPONSORS SEVER TIES
Nike, Tag Heuer and Porsche have suspended their relationship with Maria Sharapova after the five-time Grand Slam tennis champion's revelation. 

Since she was eleven years old, Sharapova has been related to Nike, who said it was "saddened and surprised".

Meanwhile, Swiss watchmaker TAG Heuer, which has been working with Sharapova for 12 years, said it would not renew its marketing contract with Maria Sharapova.

German car manufacturers Porsche were the third big-name sponsor to distance themselves from Sharapova yesterday.