Evian has become the latest sponsor to stand by Maria Sharapova following the announcement of her two-year doping ban.

The five-time grand slam champion tested positive for the banned substance meldonium at the Australian Open in January, and was handed the ban on Wednesday.

An independent tribunal appointed by the International Tennis Federation found Sharapova had not intentionally taken a banned drug but that she was using meldonium to enhance performance and bore a significant degree of fault.

Sharapova immediately announced she would be appealing immediately to the Court of Arbitration for Sport, saying in a statement on her Facebook page: “I cannot accept an unfairly harsh two-year suspension.”

Despite the judgment, Nike and HEAD announced on Wednesday they would be standing by Sharapova and now Evian has followed suit.

The bottled water giant said in a statement: “The ITF tribunal concluded that Maria Sharapova’s contravention was not intentional. Following this announcement, Evian has decided to maintain its long-lasting relationship with the champion.”

At the time the failed test was announced in March, sportswear giant Nike said it was putting its eight-year, $70million deal on hold.

But in a statement on Wednesday night, it said that it had decided to continue working with Sharapova.

The chairman of Sharapova's racket sponsor, Johan Eliasch, has robustly defended the Russian since she made the test result public, citing her as a "role model and woman of integrity" and proceeding to extend her deal.

He was highly critical of the World Anti-Doping Agency and the ITF, calling it a “flawed decision”.

Although the tribunal accepted Sharapova had not intended to take a banned substance, the verdict was damning of the 29-year-old and her agent, IMG's Max Eisenbud.

Sharapova claimed she took meldonium, a cardiac drug that was added to the banned list at the start of 2016, for health reasons having first been prescribed it by Russian doctor Anatoly Skalny in 2006.

She admitted taking it before each of her five matches at the Australian Open, while she also tested positive for it several times in 2015, including at Wimbledon, and in an out-of-competition test in February.

Sharapova did not declare taking meldonium on any doping control form and among her support team only Eisenbud and her father, who obtained the drug in Russia, knew she was taking it.

The tribunal said: “In the tribunal’s judgement, this justification advanced for the failure by Ms Sharapova to disclose her regular use of Mildronate (the brand name for meldonium) before championship matches is untenable.

“The wording of the doping control form was clear and could not reasonably be misunderstood. She must have known that taking a medication before a match, particularly one not currently prescribed by a doctor, was of considerable significance. This was a deliberate decision, not a mistake.

“Taken together with the evidence that over a period of three years she did not disclose her use of Mildronate to her coach, trainer, physio, nutritionist or any adviser she consulted through the WTA, the facts are only consistent with a deliberate decision to keep secret from the anti-doping authorities the fact that she was using Mildronate in competition.”

The tribunal went on to conclude “that she took Mildronate for the purpose of enhancing her performance”.

After stopping working with Dr Skalny in 2013, Sharapova said she entrusted Eisenbud with checking updates to WADA's banned list.

He claimed he did this every year in November when he went on holiday to the Caribbean, but he had not done so in 2015 because he did no go on holiday following a separation from his wife.

Sharapova admitted she had never personally made any effort to check whether her medication had been added to the banned list.

The tribunal rejected the evidence of Eisenbud, who manages other high-profile female players including Britain's Laura Robson, saying: "The idea that a professional manager, entrusted by IMG with the management of one of its leading global sporting stars, would so casually and ineptly have checked whether his player was complying with the anti-doping programme, a matter critical to the player's professional career and her commercial success, is unbelievable."

If the two-year ban stands, the first grand slam Sharapova will be eligible for will be the French Open in 2018.

She will no doubt be encouraged by the success of other tennis players in recent appeals to CAS, with Marin Cilic and Viktor Troicki both seeing their bans reduced.

Two of Sharapova’s other sponsors, watchmaker Tag Heuer and luxury car brand Porsche, have been less supportive than HEAD, Evian and Nike.

Porsche suspended activities with Sharapova following her failed test, and will now wait for the CAS decision.

The company said in a statement: “We have taken note of the recent International Tennis Federation ruling in the case of Maria Sharapova and are especially aware that it was decided that she was not accused of intentionally violating the World Anti-Doping Code.

“As Maria will appeal the decision, we will continue to keep all activities with her on hold until the final judgement has been reached.”

Tag Heuer announced in March it had decided not to renew Sharapova’s contract, but has not ruled out working with her again in the future.

CEO Jean-Claude Biver said: “We now have some time and, as she is suspended for two years, we are not in a hurry any more to sign a new contract today or this month. We will see later what we are going to do.”