Martina Hingis was banned for two years on Friday for testing positive for cocaine at Wimbledon last year.
The International Tennis Federation (ITF) said an independent anti-doping tribunal found that Hingis, who announced her retirement November 1 on the day she revealed the positive test, had committed an offence.
The 27-year-old Hingis denied using cocaine, but the tribunal rejected suggestions there were any doubts over her sample.
Although the five-time Grand Slam winner is now retired, her suspension is backdated to October 1 2007.
The ITF also disqualified Hingis’s results from Wimbledon in 2007 and any subsequent tournaments she played in. She also forfeits any ranking points gained and $129 481 in prize money.
Hingis lost 6-4, 6-2 to Laura Granville in the third round at Wimbledon last year. — Sapa-AP