Maria Sharapova will be provisionally suspended with effect from 12 March after failing a drug test at the Australian Open in January, the International Tennis Federation has been announced.

Sharapova revealed that she failed a drug test after testing positive for meldonium, a drug which she has taken since 2006, but which only became a prohibited substance at the start of this year.

The 28-year-old Russian made the revelation at a pre-arranged press conference in Los Angeles.

Sharapova, who has played in only one tournament this year, losing to Serena Williams in the quarter-finals of the Australian Open, said she received a letter from the ITF informing her of the failed test.                       

"I received a letter from the ITF that I failed a drugs test at the Australian Open," said Sharapova. "I take full responsibility for it.

"For the past 10 years I have been given a medicine called Mildronate by my family doctor and a few days ago after I received the ITF letter, I found out that it also has another name of meldonium, which I did not know.

"It is very important for you to understand that for 10 years this medicine was not on WADA's banned list and I had legally been taking the medicine for the past 10 years.

"But on January 1st the rules had changed and meldonium became a prohibited substance, which I had not known."

Reading from a written statement that lasted for nearly three minutes, Sharapova said she was given the substance by her family doctor to deal with sickness, a deficiency in magnesium, and her family's history of diabetes.

"I was given this medicine by my doctor for several health issues that I was having in 2006," Sharapova continued.

"Throughout my long career I have been very open and honest about many things and I take great responsibility and professionalism in my job every single day and I made a huge mistake.

"I let my fans down. I let the sport down I have been playing since the age of four and I love 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 will be given another chance to play this game.

"I know many of you thought I was retiring, but if I was ever going to announce my retirement it would probably not be in a downtown Los Angeles hotel with this fairly ugly carpet."

World number seven Sharapova has been struggling with an arm injury this year and pulled out of the upcoming Indian Wells tournament due to the injury.

The Russian added that she received a letter from WADA in December to inform her of the prohibited substances for 2016, but admitted she did not look at the list.

"It made me healthy and that is why I continued to take it," Sharapova said of the banned substance after taking a small number of questions from the floor.

"I am still working through my injury and that is the reason I withdrew from Palm Springs, because I have still not healed my injury.

Ahead of the news conference in Los Angeles, Sharapova's team said there would be a "major announcement" - leading to suggestions the Russian may announce her retirement from the sport.

Sharapova won her first grand slam as a 17-year-old at Wimbledon in 2004 and has since landed the 2006 US Open title, the 2008 Australian Open and the French Open twice, in 2012 and 2014

The highest-paid female athlete in world sport for the last 11 years, according to Forbes, Sharapova has earned a large part of her income through sponsor endorsements and has her own sweet business, Sugarpova.