AKIPRESS.COM - A bunch of international renowned brands announced on Tuesday to suspend their sponsorship deal with Maria Sharapova after the Russian tennis star admitted that she had failed a drug test.

German super car brand Porsche, which said it was disappointed by the news, has decided to cancel all events involving the former tennis world No. 1 while her use of banned drug is investigated by the International Tennis Federation.

Sportswear company Nike has already terminated its long-running sponsorship of Sharapova, saying it was "saddened and surprised" by the news.

"We have decided to suspend our relationship with Maria while the investigation continues," Nike's statement read.

Swiss watchmaker TAG Heuer said it would not extend its sponsorship contract with the five-time grand slam champion.

On Monday, Sharapova announced in Los Angeles that she was informed by the World Anti-Doping Agency that she failed a drug test at the Australian Open in January.

The 28-year-old star said the test found her positive to a substance called "mildronate", which she has been taking in the last 10 years for health issues.

Mildronate is also known as meldonium, which is used to treat diabetes and low magnesium. It was added to the prohibited list this year.

Earlier in the day, the Russian Tennis Federation gave its public blessing to the tennis star, saying they are confident that Sharapova would "withstand this test with dignity," and promising to do everything they can do help her, Xinhua reports.