Diana_Taurasi_Beijing_August_2008December 24 - America's double Olympic basketball gold medallist Diana Taurasi is facing the prospect of missing London 2012 after testing positive for a banned drug.

The WNBA star, who plays for the Phoenix Mercury, was suspended after she tested positive in Turkey for a banned supplement, her lawyer Howard Jacobs has confirmed.

Like most WNBA players, Taurasi spends her off-season playing overseas and she was appearing for Istanbul's Fenerbahce.

She spent the last four years in Russia before being signed with the Turkish team this season.

Jacobs said the basketball star's A-sample tested positive for a stimulant, and she is waiting for a B-sample to be tested.

A press release from the Turkish Basketball Federation said she tested positive for Modafinil, which is used to help sleep disorders, like narcolepsy.

"[She's] hoping the 'B' sample will show that the 'A' was a mistake," Jacobs said.

"She doesn't believe that she's ever taken anything that's banned; the most logical explanation at this point is that the test is simply wrong."

Under the rules of the World Anti-Doping Agency (WADA), Taurasi faces a two-year ban if she is found guilty.

Modafinil has been involved in several doping-related controversies.

American sprinter Kelli White, who won the 100 and 200 metres at the 2003 World Championships in Paris, had both of her medals stripped after testing positive for the substance.

Modanafil was also one of the cocktail of drugs that banned British sprinter Dwain Chambers admitted to taking.

The former University of Connecticut star has led the WNBA in scoring four times and won the league's MVP award in 2009.

Taurasi helped lead the Mercury to the WNBA championship in 2007 and 2009.

Taurasi played on the US teams that won gold at the 2004 and 2008 Olympics and, in October, she helped lead the Americans to a gold medal at the World Championships.

But, under the rules of the International Olympic Committee, she would miss London 2012 because they ban anyone from appearing in the next Winter or Summer Games if they have served a doping suspension of six months or longer.