Maria Sharapova has been banned for two years by the International Tennis Federation for using a prohibited drug, the BBC reports.

The Russian was provisionally banned in March after testing positive for meldonium at January’s Australian Open.

The heart disease drug, which 29-year-old Sharapova says she has been taking since 2006 for health issues, became a banned substance on 1 January 2016.

The five-time Grand Slam winner said she “cannot accept” the “unfairly harsh” ban – and will appeal.

Sharapova will challenge the suspension, which is backdated to 26 January 2016, at the Court of Arbitration for Sport (Cas).