Up to 31 athletes from six sports and 12 different countries could be banned from competing at the Rio de Janeiro Olympics after the International Olympic Committee (IOC) found positive results in retests of 454 doping samples from Beijing 2008.
IOC president Thomas Bach said the measures would show dopers that they "had no place to hide" after
More athletes could also be barred from competing at this year's Games once 250 more results from London 2012 have been tested using what the IOC described as "the very latest scientific analysis methods".
The organisation has also instructed the World Anti-Doping Agency to initiate a full investigation into allegations that testing at the 2014 Winter Olympics in Sochi was compromised by the Russian Federal Security Service in some cases.
"All these measures are a powerful strike against the cheats we do not allow to win," Bach said.
"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 competitions, including the Rio anti-doping laboratory, so that the Olympic magic can unfold in Rio de Janeiro."