Maria Sharapova has vowed to appeal the two-year suspension handed to her for failing a drugs test at the Australian Open.

Sharapova’s ban, announced by the International Tennis Federation on Wednesday, is backdated to January 26th this year, when she tested positive for prohibited substance meldonium.

The five-time grand slam champion will miss the Olympic Games in Rio this summer while the earliest grand slam she could next enter is the French Open in 2018.

Sharapova claimed in March she was prescribed meldonium in 2006 for “several health issues” and was unaware it had been added to the World Anti-Doping Agency’s prohibited list from January 1st this year.

An Independent Tribunal concluded, however, that while Sharapova had not deliberately broken anti-doping rules, for which she would have received a four-year ban, she had taken the substance to enhance her performance and failed to make necessary checks regarding its legality.

Sharapova described the two-year suspension on Wednesday as “unfairly harsh” and says she will lodge an appeal 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 wrote on Facebook.

“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.”

Sharapova’s results at the Australian Open, where she lost to Serena Williams in the quarter-finals, have been disqualified, with her prize money and ranking points earned in Melbourne also removed.

Meldonium was on WADA’s watch list last year and in September the agency announced it would be banned from the start of 2016, citing “evidence of its use by athletes with the intention of enhancing performance”.

The substance, which carries a brand name of ‘mildronate’, is principally used for cases of ischaemic heart disease but its ability to boost blood-flow can also improve an athlete’s endurance.

Sharapova was initially prescribed meldonium 10 years ago to alleviate cold-related illnesses but, despite discontinuing her relationship with the doctor in 2012, continued routinely taking it on the morning before matches.

None of Sharapova’s team, except her agent Max Eisenbud, were aware she was still ingesting the substance and she failed to disclose its use on any doping control form between 2014 and 2016.

The tribunal wrote: “It may be that she genuinely believed that Mildronate had some general beneficial effect on her health but the manner in which the medication was taken, its concealment from the anti-doping authorities, her failure to disclose it even to her own team, and the lack of any medical justification must inevitably lead to the conclusion that she took Mildronate for the purpose of enhancing her performance.”

Sharapova had argued the ITF should have made extra efforts to flag up the addition of meldonium to Wada’s banned list, particularly given a number of other players had tested positive for the drug in 2015.

The ITF contended, however, it was not made aware of last year’s test results until March this year and in any case said it was committed to protecting the anonymity of those reports.

After the first announcement of the 2016 Prohibited List in September, it appears players were sent another direct email in December referring to the changes, as well as postings on the ITF website and digital ‘wallet cards’ given to players listing the banned substances.

Sharapova, who has pocketed more than 36million in career prize money, has already seen her commercial relationships cut with the likes of Nike and Porsche. She protested the ban would disproportionately damage her earnings, sponsorship and reputation.

The report, however, said: “There is nothing unfair in the rules being fairly and equitably applied to this player as to any other athlete subject to the WADA Code, whether professional or amateur.”

Sharapova reached the French Open final as well as the Wimbledon semi-final last year and she began 2016 ranked number four in the world.

Her chances, however, of rejoining the elite after two years away from the game appear slim, particularly given the Russian will be almost 31 when her suspension ends.

The tribunal concluded: “The contravention of the anti-doping rules was not intentional as Ms Sharapova did not appreciate that Mildronate contained a substance prohibited from 1 January 2016.

“However she does bear sole responsibility for the contravention, and very significant fault, in failing to take any steps to check whether the continued use of this medicine was permissible.

“If she had not concealed her use of Mildronate from the anti-doping authorities, members of her own support team and the doctors whom she consulted, but had sought advice, then the contravention would have been avoided. She is the sole author of her own misfortune.”