The Italian tennis player Filippo Volandri has been suspended for three months after testing positive for a banned stimulant.
The 27-year-old will now miss next week's Australian Open.
The International Tennis Federation says a sample provided by Volandri last year contained salbutamol at a concentration greater than permitted.
The 27-year-old, ranked 109th in the world, blamed his failed test on an inhaler he takes for asthma.
Volandri says he had a medical exemption certificate to use Ventolin, which contains salbutamol, to treat his condition but was deemed to have exceeded his limit.