The second sample of Ukraine's Olympic heptathlon silver medalist Lyudmila Blonska, who has been provisionally suspended from the Beijing Games, tested positive for steroids, the IOC said on Thursday.
"The International Olympic Committee disciplinary commission held a hearing today in relation to her adverse analytical finding. The A and B sample analysis were positive for the substance methyltestosterone," an IOC official told Reuters.
The substance is an anabolic steroid.
"At the end of the hearing ... the commission decided to provisionally suspend Blonska from all competitions with immediate effect and to provisionally cancel her accreditation, until the final decision has been pronounced by the IOC Executive Board," the official said.
The athlete, who faces a lifetime ban as a second-time offender, has also been removed from the long jump final she was due to compete in on Friday.
Blonska will now await the executive board ruling, on Friday, which will most likely officially kick her out of the Games.
Blonska had returned to competition in 2005 after serving a two-year doping ban, but tested positive again after her silver medal performance on August 17.
The drugs test was conducted at 2 a.m the morning after her competition. The test was a routine procedure for all top five finishers in Beijing.
Under World Anti-Doping Agency rules, Blonska risks a lifetime ban if the IOC rules she has again violated anti-doping rules.
Blonska won silver on Saturday behind compatriot Nataliia Dobrynska. American Hyleas Fountain took bronze. Tatiana Chernova of Russia finished fourth.
Four athletes, excluding Blonska, have been caught doping and been dismissed from the Olympics.
A Spanish cyclist, a North Korean shooter, a Vietnamese gymnast and a Greek hurdler have failed doping tests, with the IOC enforcing the most sophisticated and far-reaching testing program ever introduced during an Olympic Games.