The International Olympic Committee has revealed it will retest 5,000 doping samples from the Beijing Games to check for traces of a new blood-booster drug.
The IOC said its doping lab in Switzerland would be specifically testing for Cera, an advanced version of endurance-enhancing hormone EPO. The decision comes after French officials detected Cera during retesting of Tour de France samples.
However, it is thought the retests will cover all sports, not just cycling.
The IOC's announcement comes 48 hours after reanalysed samples from the Tour de France using the new technology unearthed two drug cheats - Germany's Stefan Schumacher, a double stage winner on this year's race, and Italian Leonardo Piepoli.
The original urine tests had raised suspicions but proved inconclusive.
"Basically, the IOC have a policy that allows them to go back up to eight years to retest a sample, but this is the first time they've done so on this scale," reports BBC sports news correspondent Gordon Farquhar.
"What they're looking at is a new test for third generation EPO. It's a blood-boosting drug which allows more oxygen to be carried in the system, therefore aiding stamina.
"At the moment, cyclists from the Tour de France are having their samples retested and already two more have been found to have been cheating using the substance Cera.
"Now the IOC is going to do the same. They will talk to the World Anti-Doping Agency (Wada) to create a protocol for this, which basically means creating a legal format for the retests, so they can go ahead and examine a substantial number of samples."
The IOC disqualified six athletes for doping during the 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, with Belarusian hammer throwers Vadim Devyatovskiy and Ivan Tsikhan having been given until 17 October 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.