ZURICH: Switzerland's Martina Hingis announced her retirement from competitive tennis here citing ongoing suspicions of doping as the reason she is giving up the game.

It is the second time that Hingis, one of the teenaged stars of the game in the 1990s, has retired from the professional circuit.

The 27-year-old Swiss star, who has five Grand Slams to her name, first retired in 2003 due to persistent ankle injury problems.

She returned to the top flight in 2006, but despite showing her potential by winning three titles she has struggled to recover from a string of injuries and health-related problems.

Hingis brought her season to a premature end last month because of hip problems but had vowed to return to action.