As many as 31 athletes from six different sports could be banned from competing in this summer's Olympic Games in Rio de Janeiro.
Olympic chiefs made the announcement on Tuesday and comes after International Olympic Committee (IOC) retested 454 selected doping samples from the Beijing Olympic Games in 2008.
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The IOC have added that the retests were completed using the very latest scientific analysis methods and procedures and that it is also awaiting the results of a further 250 retests from the London Games in 2012.
The committee has now opened disciplinary proceedings against the unidentified athletes which are said to come from 12 different countries.
"All these measures are a powerful strike against the cheats we do not allow to win," IOC president Thomas Bach explained.
"They show once again that dopers have no place to hide. We keep samples for 10 years so that the cheats know that they can never rest.
"By stopping so many doped athletes from participating in Rio, we are showing once more our determination to protect the integrity of the Olympic competition."
The samples that have been tested had been stored at the IOC laboratory in Lausanne, Switzerland.
As a result of the news, wider testing of medallists from Beijing and London will now be undertaken.
Earlier this year, Ireland's distance walker Rob Heffernan was upgraded to a bronze medal after the winner of his discipline at London 2012 tested positive for drugs.
At present, it is not clear if Irish competitors are involved in the re-testing procedures or whether they might benefit from retrospective measures.
