Former world No 1 Maria Sharapova has been banned for two years by the International Tennis Federation (ITF) after failing a drug test at this year's Australian Open.

Sharapova, the world's highest-paid female athlete and a five-times Grand Slam champion, stunned the sporting world in March when she announced that she had tested positive for meldonium, a substance she had been taking since 2006 but one that was added to the banned list on January 1 this year.

Sharapova's Grand Slam titles
Australian Open: 2008
French Open: 2012, 2014
Wimbledon: 2004
US Open: 2006

In a statement on Wednesday, the ITF said the 29-year-old Russian's ban would be back-dated to January 26 this year, meaning her results from the Australian Open where she reached the quarter-finals, would be disqualified.

Minutes after the ITF’s decision was announced, Sharapova said she would appeal against the ban to the Court of Arbitration for Sport.

"While the tribunal concluded correctly that I did not intentionally violate the anti-doping rules, I cannot accept an unfairly harsh two-year suspension," Sharapova said in a statement.

"The tribunal, whose members were selected by the ITF, agreed that I did not do anything intentionally wrong, yet they seek to keep me from playing tennis for two years. I will immediately appeal the suspension portion of this ruling to CAS, the Court of Arbitration for Sport."

Meldonium was added to the World Anti-Doping Agency's (WADA) list of banned substances at the start of the year after evidence that it boosted blood flow and enhanced athletic performance.

Sharapova was provisionally suspended by the ITF in early March, when she announced at a news conference in Los Angeles that she had failed a doping test in January.

She said then she was not aware that WADA had barred athletes from using meldonium, also known as Mildronate, as of January 1.

Source: Al Jazeera and agencies