Nike has suspended ties with tennis player Maria Sharapova following a major drug scandal that has the sports world reeling.

The Russian tennis champion said Monday she failed a drug test at the Australian Open, testing positive for Meldonium, a drug that can enhance stamina. Sharapova said she's been taking the drug for health reasons over the last decade.

Meldonium became a banned substance as of Jan. 1 of this year.

In 2010, Sharapova extended her sponsorship deal with Nike for eight years for a reported $70 million, in a deal that included her own line of clothing.

The tennis player also has lucrative endorsement deals with American Express, Avon, Evian, Porsche and Tag Heuer.