Maria Sharapova has been handed a two-year ban from tennis, subject to an appeal, after testing positive for banned substance meldonium. The 29-year-old will miss the Rio 2016 Olympic Games after being found guilty of anti-doping rule violation by the International Tennis Federation (ITF) following a two-day investigation.

The backdated punishment will see Sharapova banned until 28 January 2018 and throws into major doubt her future in a sport where she is a five-time grand slam champion. The world's highest-paid female athlete, according to Forbes, will forfeit the ranking points and prize money from the Australian Open after she tested positive following a quarter-final defeat to Serena Williams.

In a statement via her Facebook page, Sharapova confirmed she will appeal 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," she said. "I have missed playing tennis and I have missed my amazing fans, who are the best and most loyal fans in the world.

The 29-year-old was provisionally suspended by the ITF on 12 March pending an investigation after testing positive for the substance – which tackles heart disease – and was added to the World Anti-Doping Agency's (Wada) banned list for the start of 2016. Sharapova pleaded innocent at a press conference earlier in the year and claimed she was unaware the substance was now prohibited, having taken the drug for the past decade.

Though the former world number one admitted she "made a huge mistake" after failing the test, she was hopeful of escaping a ban due to her extenuating circumstances and the lack of research into meldonium. Recent high-profile incidents of doping in tennis have involved the likes of Marin Cilic and Viktor Troicki, who were banned for four and 12 months respectively.

Despite being suspended from the sport and Russia's participation being in major doubt, Sharapova was named in the team for the Olympic Games as she awaited results of an investigation by tennis's governing body, which began in London on 17 May. She was omitted from the entry list for this year's Wimbledon, which starts on 27 June, and dropped by primary sponsor Nike in the wake of the positive test. Wada announced prior to the hearing that tests taken before 1 March that registered less than one microgram would receive no punishment.

Since meldonium was banned at the turn of the year a number of athletes, many of whom hail from Russia, have also tested positive – including boxer Alexander Povetkin – but several have escaped being reprimanded by the country's anti-doping association. The nation are currently fighting a ban from the Olympics after a Wada report found evidence of state-sponsored doping and they face an anxious wait to discover if they will be readmitted in time for Rio 2016.