Nike, TAG Heuer suspend ties with Sharapova

Sharapova had been taking meldonium for a decade due to health reasons and said she was not aware it was added to the World Anti-Doping Agency's (WADA) list of prohibited substances as of January 1 this year.

Maria Sharapova admitted to a failed drug test on Monday.

Two of Maria Sharapova’s top sponsors have suspended ties with the Russian tennis star after she admitted to failing a doping test.

Former world number one Sharapova revealed on Monday that she tested positive for meldonium at the season's opening Slam in Melbourne in January.

Sharapova had been taking meldonium for a decade due to health reasons and said she was not aware it was added to the World Anti-Doping Agency's (WADA) list of prohibited substances as of January 1 this year.

And Nike wasted little time responding to the situation, releasing a statement which read: "We are saddened and surprised by the news about Maria Sharapova.

"We have decided to suspend our relationship with Maria while the investigation continues. We will continue to monitor the situation."

Swiss watchmaker TAG Heuer said it would not renew its marketing contract with Maria Sharapova. “Maria Sharapova was under contract with TAG Heuer until December 31th, 2015. We had been in talks to extend our collaboration,” a company statement said.

“In view of the current situation, the Swiss watch brand has suspended negotiations and has decided not to renew the contract with Ms Sharapova.”

Sharapova - who lost to Serena Williams in the quarterfinals at Melbourne Park - will be provisionally suspended with effect from March 12, the International Tennis Federation (ITF) said.

The 28-year-old had already withdrawn from this week's BNP Paribas Open at Indian Wells due to a left forearm injury, which has proved troublesome.