World tennis No 1 Serena Williams has backed Maria Sharapova for showing "a lot of courage and heart" after admitting to failing a drugs test.

The Russian, facing a one-year ban after testing positive for meldonium, made the stunning announcement at a press conference on Monday. Sharapova, 28, said she had tested positive for the banned substance during the Australian Open, but said she had been taking the drug since 2006 for health reasons and did not realise it was now banned. 

Sharapova said she "made a huge mistake" but maintained her innocence.

Williams, arguably the most dominant women's player ever, lent he support to Sharapovs at a press conference of her own.

"It's just taking responsibility, which she admitted she was willing to do and wanted to do, so I just hope for the best for everyone involved," Willaims said.

"To be honest I think in sport and in life there's always a double standard and everyone knows that, whether it's a race thing or a sex thing.

"However, this is a different thing and she said she's ready to take responsibility and that shows a lot of courage and a lot of heart, but she's always shown that in her career.

"I am not concerned [by damage to the WTA Tour], there are a lot of stars and personalities on the WTA Tour."


Williams and Sharapova during the Australian Open

Sharapova is facing a lengthy ban and has alreeady been dropped by several sponsors, including Nike, Tag Heuer and Porsche.

Later, Caroline Wozniacki echoed Serena Williams' sentiment, but added that athletes have to "triple check" everything.

"I don't think there's any more to add, I think Serena said it," said the 25-year-old Dane.

"Anytime you take any medication we double and triple check because even things like cough drops or nasal sprays can be on the list.

"So, as athletes we try to really make sure there's nothing in them that can give an advantage."