The IOC's declaration yesterday followed the publication of a report by World Anti-Doping Agency investigator Richard McLaren.
This said that more than 1,000 Russian athletes, including medal winners at the London and Sochi games, had benefited from a state-backed campaign of doping and drug test cover-ups.
Russian Deputy Prime Minister Vitaly Mutko, who was sports minister at the time of the 2012 and 2014 Olympics, tells Russian state agency R-Sport that "the IOC has now decided to retest all the samples; let them retest."