Watchmaker Tag Heuer has revealed that it will not renew its sponsorship contract with Maria Sharapova after the tennis star admitted to failing a drug test earlier this year at the Australian Open.

Sharapova, 28, said yesterday that she had tested positive for meldonium, a drug which she had been taking for 10 years but one that was added to the World Anti-Doping Agency's banned substance list from the start of 2016.

A statement from Tag Heuer read: "Maria Sharapova was under contract with Tag Heuer until December 31, 2015. We had been in talks to extend our collaboration.

"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's sportswear provider Nike has also suspended its contract with the Russian until WADA's investigation is complete.