The career of Russian former world number one Maria Sharapova was in tatters yesterday after she was given a two-year ban by the International Tennis Federation (ITF) following her positive test for the banned drug meldonium.

In a statement the ITF said the five-time grand slam champion's ban would be backdated to January 26 this year, meaning her results and prize money from the Australian Open, where she reached the quarter-finals, would be withdrawn.

Sharapova, 29, said she would appeal to the Court of Arbitration for Sport, describing the punishment as "unfairly harsh".

She said an independent tribunal in London on May 18-19 had found that she had not intentionally violated anti-doping rules.

On its website, the ITF said the ban, which could have been as long as four years, had been backdated due to Sharapova's "prompt admission" of taking the substance, and would end on midnight of January 25, 2018.

Sharapova has regularly battled back from serious injuries during her glittering career.

But the two-year ban means she will not be eligible to play until after the 2018 Australian Open, when she will be 30.

"The ITF spent tremendous amounts of time and resources trying to prove I intentionally violated the anti-doping rules and the tribunal concluded I did not," she said on Facebook.

The ITF had sought a four-year suspension, but the tribunal rejected that, she said.

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

The tribunal found that Sharapova had taken meldonium before each of her five matches at this year's Australian Open, where she lost to Serena Williams.