Six medallists from the 2008 Beijing Olympics have been stripped of their medals after re-tests of their 2008 samples tested positive for doping.
The medallists include four weightlifters, a wrestler and a steeplechase runner, who come from Russia, Uzbekistan, Belarus, Kazakhstan and Ukraine.
The International Olympic Committee announced the decisions in the latest sanctions imposed on athletes whose stored samples came back positive after being retested with improved methods.
The six medalists all tested positive for steroids.
The IOC stores doping samples for 10 years to allow them to be reanalyzed when enhanced techniques become available. The IOC recorded a total of 98 positive cases in recent resting of samples from Beijing and the 2012 London Olympics.
Stripped of silver medals Wednesday were freestyle wrestlers Soslan Tigiev of Uzbekistan (66-74 kilogram division) and Taimuraz Tigiyev of Kazakhstan (84-96 kg) and weightlifters Olha Korobka of Ukraine (75 kg) and Andrei Rybakov of Belarus (85 kg).
Losing bronze medals were Russian steeplechaser Ekaterina Volkova and Belarusian weightlifter Anastasia Novikova (53 kg).
Also disqualified were Cuba's Wilfredo Martinez, who finished fifth in the men's long jump; Nigerian-born Spaniard Josephine Onyia, who was eliminated in the semifinals of the 100-metre hurdles; and weightlifter Sardar Hasanova of Azerbaijan, who competed but did not finish in the men's 62-kg division.