Russian tennis star Maria Sharapova admitted to failing a drug test at the Australian Open on Monday. Now three major sponsors are cutting ties.

FOX's Kitty Logan reports:

The sportswear company Nike and the Swiss watch brand TAG Heuer confirmed they're cutting ties with Maria Sharapova.

The carmaker Porsche also says it will suspend the player as brand ambassador. Sharapova admitted taking the drug meldonium, which has only been banned since the start of the year.

She insists she was taking it for health reasons. It's not yet clear what penalty Sharapova may face. But she says she hopes to have another chance to play tennis in future. And the head of Russia's tennis federation says he believes Sharapova will compete at the Rio Olympics.

In recent years, she's become one of highest earning female sports stars in the world.

In London, Kitty Logan, FOX News.