The world governing body for athletics, the IAAF, has decided to appeal against the acquittal of Greek sprinters Costas Kenteris and Katerina Thanou on charges related to missing three doping tests.
The athletes were cleared by their national federation on March 18 in a shock decision after the Greek authorities said the pair were victims of incorrect procedures in notifying them of doping tests, including one just before the Athens Olympics.
The athletes spectacularly withdrew from last year's Games days before they were due to race in front of their home crowd.
They are now suspended again pending the result of the IAAF's appeal.
Kenteris, 31, who won a 200 metres gold medal at the 2000 Sydney Games, and Thanou, 30, a 100 metres silver medallist at the same Olympics, face maximum two-year bans if they are found guilty.
The sprinters have consistently denied they were at fault and responsible for the Olympic movement's biggest athletics scandal since 100 metres gold medallist Ben Johnson tested positive for drugs at the 1988 Seoul Olympics.
The International Olympic Committee (IOC) said earlier on Friday that it would conduct its own investigation into the sprinters if they tried to compete at the 2008 Beijing Games.
The two athletes still also have to face a trial on charges brought separately by Greek prosecutors of missing the drug tests and faking a motorcycle accident to avoid testing in the 2004 Athens Games case. No date has yet been set for the trial.
