The International Olympic Committee will retest doping samples from the Beijing Games to check for traces of a new blood-boosting drug and other banned substances.
The move, announced Wednesday, is designed to search in particular for a performance-enhancer that was only recently detected during retesting of samples from the Tour de France.
The Beijing samples — across all sports — are being sent to the World Anti-Doping Agency accredited laboratory in Lausanne, IOC spokeswoman Emmanuelle Moreau said.
"This clearly demonstrates the determination that there is zero tolerance (on doping), and that we will use all the means available to catch the cheaters," IOC vice president Thomas Bach of Germany told The Associated Press.
The IOC conducted more than 5,000 drug tests during the Beijing Games, including nearly 1,000 blood screenings.
IOC medical director Patrick Schamasch said officials are still considering how many and which samples to retest.
"The decision will be based on intelligence, on information we receive and many other parameters," he told the AP.
The time frame for the testing process hasn't been finalized.
"Once we decide how many tests, and who to test, then it will not take long," Schamasch said. "We're not pushed by anyone. We will do it when we are ready."
The IOC stores samples from the Olympics for eight years, leaving open the possibility to retest them when new detection methods are devised.
Any athletes caught by new tests can be sanctioned retrospectively and be stripped of their results and medals.
The IOC previously retested some samples from the 2002 Salt Lake City Winter Games to look for THG, the designer steroid at the center of the BALCO scandal. No positives were found.
The Beijing samples will be reopened and tested for CERA, a new generation of the endurance-enhancing hormone EPO. The substance boosts an athlete's performance by increasing the number of oxygen-rich blood cells.
A new blood test used by the French Anti-Doping Agency detected CERA during retesting of samples from Tour de France riders. The original urine tests had raised suspicions but proved inconclusive.
Officials confirmed Tuesday that German rider Stefan Schumacher, and Italians Riccardo Ricco and Leonardo Piepoli had tested positive for CERA at the Tour. The three riders combined to win five of the Tour's 21 stages.
"The idea is to retest across the sports, not solely on cycling," Moreau said. "They will retest for all the new substances that are currently detectable, not only CERA."
She said the tests will likely be targeted on endurance sports in which CERA would be most beneficial to athletes.
Schamasch said the IOC will test blood samples for CERA, but tests will also be carried out to detect other drugs which he declined to identify.
"We have indication of other substances," he said.
The IOC decision was welcomed by Olympic and anti-doping officials.
"We suggest that athletes who may be tempted to cheat keep this reality in mind and we believe that retrospective testing will serve as a strong deterrent," WADA president John Fahey said.
Michael Vesper, director general of the German Olympic Sports Union, described the move as a "thunderbolt."
"All undiscovered cheats will be shaking now," he said.
Andy Parkinson, head of operations of Drug-Free Sport in Britain, said the initiative "sends a great message."
"Long gone are the days when an athlete gets a negative test after a competition and disappears with the medal forever," he said. "Athletes who cheat are not safe even eight years after competitions."
Bach said Tuesday that the future of men's road cycling in the Olympics could be threatened unless the sport cleans up its act under the aegis of the international cycling union, or UCI.
If the entire sport doesn't pull together to improve the situation, "then you have to consider giving men's road cycling a pause" from Olympic participation, Bach told the AP in a telephone interview.
In a statement Wednesday, Moreau said, `The IOC will continue to support the UCI — and any other international federation — as long as it is deploying meaningful and credible means and efforts to fight against doping."
The IOC disqualified six athletes for doping during the Aug. 8-24 Beijing Games — Ukrainian heptathlete Lyudmila Blonska, Ukrainian weightlifter Igor Razoronov, Greek hurdler Fani Halkia, North Korean shooter Kim Jong Su, Spanish cyclist Isabel Moreno and Vietnamese gymnast Thi Ngan Thuong Do.
Three other cases are still pending. The IOC has given Belarusian hammer throwers Vadim Devyatovskiy and Ivan Tsikhan until Oct. 17 to provide more information explaining why they tested positive for testosterone. A decision is due shortly in the case of Polish canoeist Adam Seroczynski, who tested positive for clenbuterol.
In addition, dozens of athletes around the world were caught for doping before the Olympics in pre-games tests.