China's top male backstroker Ouyang Kunpeng has been banned for life for doping, officials have confirmed, dealing the host nation an embarrassing blow just 42 days before the start of the Beijing Olympics.
Ouyang tested positive for the anabolic steroid clenbuterol, Zhao Jian, head of the anti-doping office at the Chinese Olympic Committee (COC) confirmed.
Chinese swimmers were embroiled in a series of doping scandals in the 1990s but the country's sporting authorities had pledged to weed out drug cheats before the Beijing Games.
The 25-year-old Ouyang won three individual silver medals at the 2006 Asian Games and three golds at the 2003 world university games.
"The swimmer Ouyang Kunpeng tested positive in an out-of-competition test on May 1," read an official Chinese Swimming Association notice posted on the website of the official China Sports Daily paper.
"The Chinese Swimming Association decided to give him a life ban ... although we have done lots of work, this positive case still happened, which is a deep lesson for us.
"We are going to take a clear stand on anti-doping work and firmly crack down on any violations."
His coach Feng Shangbao has also been banned for life, the notice said.
Ouyang is the biggest-name Chinese swimmer to fail a dope test for several years, although suspicions of systematic doping that accompanied the country's sudden emergence as a swimming power have proved hard to completely erase.
In the most notorious case, four Chinese swimmers failed pre-competition doping tests for the diuretic triamterene before 1998 world championships in Perth.
Another female swimmer, Yuan Yuan, and her coach, Zhou Zhewen, were disqualified from the championships after being caught with 13 vials of the muscle-building human growth hormone at Sydney airport.