The International Olympic Committee, staying true to its pledge to fight doping, said Tuesday that six athletes have been nabbed by retesting their blood samples for CERA, an advanced version of the blood-boosting hormone EPO.
A person familiar with the results told The Associated Press the latest tests caught three track and field athletes, two cyclists and one weightlifter.
The person, speaking on condition of anonymity because the names haven't been released by the IOC, said a male track and field athlete who won only one gold medal was one of the athletes. The other medalist was in cycling.
The IOC did not identify the athletes or sports involved, saying it was notifying the competitors through their national Olympic committees.
The Italian Olympic Committee said one of the six was an Italian athlete, though it declined to name him. The Italian news agency ANSA identified him as cyclist Davide Rebellin, silver medalist in the road race.
U.S. Olympic Committee spokesman Darryl Seibel said the federation hadn't received notification from the IOC of any adverse findings involving a U.S. athlete.
"Unless we hear otherwise, we are treating no news as good news," Seibel said.
The IOC reanalyzed a total of 948 samples from Beijing after new lab tests for CERA and insulin became available following the Olympics. The testing began in January and focused mainly on endurance events in cycling, rowing, swimming and athletics.
"The further analysis of the Beijing samples that we conducted should send a clear message that cheats can never assume that they have avoided detection," said Arne Ljungqvist, chairman of the IOC medical commission.
Coaches, athletes and anti-doping organizations welcomed the announcement, saying it helps restore credibility to Olympic sports.
"I'm in favor of anything they're doing to clean up the sport," said Glen Mills, coach of Jamaican sprinter Usain Bolt, who won three gold medals in the 100 meters, 200 meters and 4x100 relay -- all in world-record times.
Bolt "has not heard anything -- and he will not hear anything," Mills said by telephone from Jamaica.
The IOC will wait for word from the national Olympic bodies before holding any disciplinary hearings. Athletes found guilty of doping face being disqualified from the Olympics and stripped of any medals they won.
The positive findings were based on "A" sample test results. Athletes will be allowed to ask for a testing of their backup "B" samples.
In the meantime, national and international bodies are free to impose provisional suspensions of athletes, the IOC said.
A Greek race walker, Athanasia Tsoumeleka, announced in January that she had tested positive in the new Beijing checks. Tsoumeleka, who finished ninth in Beijing in the 20K walk, was charged by a Greek prosecutor earlier this month with using banned drugs.
The IOC previously disqualified nine athletes for doping at the Aug. 8-24 Olympics. In addition, there were six doping cases involving horses in the equestrian competition.
The IOC has already stripped four athletes of Beijing medals -- Ukrainian heptathlete Lyudmila Blonska (silver), Belarusian hammer throwers Vadim Devyatovskiy (silver) and Ivan Tsikhan (bronze) and North Korean shooter Kim Jong Su (silver and bronze).
The IOC is storing doping samples for eight years so they can be tested retroactively when new detection methods are developed.
The World Anti-Doping Agency welcomed the IOC findings. Under the WADA code, athletes can be disciplined up to eight years from the date of a doping violation.
"We suggest that athletes who may be tempted to cheat keep this reality in mind," WADA president John Fahey said. "We believe that retrospective testing serves as a strong deterrent."
Lauryn Williams, a member of the U.S. track and field team in Beijing and a 2004 silver medalist in the 100 meters, also backed the testing system.
"To go ahead and weed out the cheaters is a good thing," she said. "To find out there are additional cheaters is not a great thing."