The International Olympic Committee (IOC) said it would conduct its own investigation into Greek sprinters Costas Kenteris and Katerina Thanou if they tried to compete at the Beijing Games in 2008.
The pair were acquitted by the Greek athletics federation in March of all charges related to missing three doping tests, including one on the eve of last year's Athens Olympics.
"The granting of an accreditation for the 2008 Games would depend on a further inquiry by the IOC," president Jacques Rogge said on Friday.
The International Association of Athletics Federations (IAAF) is considering appealing Kenteris and Thanou's acquittal in the Court of Arbitration for Sport. World Anti-Doping Agency (WADA) president Dick Pound has said his organisation would also consider an appeal.
"Even if the case is exhausted at the level of the IAAF...we have the legal possibility to reopen the case," said Rogge at the Oceania National Olympic Committee (ONOC) general assembly.
"I cannot speculate on the decision of the IAAF neither the eventual decision of the Court of Arbitration for Sport but one thing is clear, this case is not over."
Former Olympic 200 metres champion Kenteris and Thanou pulled out of the Athens Games before they started.
The IAAF suspended the two athletes in December pending the resolution of their cases but a Greek disciplinary commission ruled the athletes were merely victims of incorrect procedures, although their former coach Christos Tzekos was banned for four years for his role in the affair.
Kenteris and Thanou, a silver medallist at the 2000 Sydney Olympics, still have to face trial on charges brought separately by Greek prosecutors of missing the drugs tests and faking a motorcycle accident to avoid testing at the Athens Games.