More athletes have been stripped of medals following re-tests. Ten competitors from the 2008 Beijing Games have lost their awards after failing new and more stringent re-checks. That group is among 16 athletes to fail in this latest round of testing performed by the IOC.

Most of the competitors were wrestlers and weightlifters, including three silver medallists -- Khasan Baroev from Russia in the men's 120-kilo Greco-Roman wrestling, Vitaliy Rahimov from Azerbaijan in the men's 60-kilo Greco-Roman wrestling, and Irina Nekrassova from Kazakhstan in the women's 63-kilo weightlifting.

Others included four bronze medallists in weightlifting. 98 samples have come back as positive for banned substances in re-analysis from the 2008 and 2012 Games, as the IOC has attempted to root out cheats.

The IOC stores samples for a decade to test with newer methods, or to analyze performance-enhancing substances that have yet to be identified.