Global sportswear brand Nike has suspended its relationsionship with Russian tennis star Maria Sharapova after it was revealed she failed a drug test at this year’s Australian Open.

Nike, one of Sharapova’s biggest sponsors, confirmed the decision in a short statement following the announcement the 28-year-old tennis star had tested positive for Meldonium.

“We are saddened and surprised by the news about Maria Sharapova,” the Nike statement read.

“We have decided to suspend our relationshi with Maria while the investigation continues. We will continue to moniter the situation.”

Sharapova, a teenage tennis prodigy who became the third-youngest Wimbledon champion, has taken “full responsibility” after failing the test.

The five-time grand slam champion – also the highest-paid woman in sports – has been taking the drug since 2006.

She is the seventh athlete in a month to test positive for meldonium, which is used to treat diabetes and low magnesium, and was only banned by the World Anti-Doping Agency (WADA) as of January 1, 2016.