Russian weightlifters Nadezda Evstyukhina, who won bronze in the women's 75-kilogram category, and Marina Shainova, a silver medalist in women's 58kg, tested positive, as did Armenia's men's 69kg bronze medalist Tigran Martirosyan, the IOC said.

Tatyana Firova, part of the Russian silver medal-winning 4x400m team, also tested positive and the team was disqualified, the Committee added.

Two more weightlifters who did not finished in the top three, Alexandru Dudoglu of Moldova and Intigam Zairov of Azerbaijan, completed the group of six.

Doping controversies

All of those sanctioned were ordered to return any medals, pins or diplomas they had won in Beijing.

They are the latest in a series of athletes who have tested positive for illegal substances in IOC retests of samples from Beijing and the London Games in 2012.

Doping controversies overshadowed the buildup to this year's Rio Olympics and some Russian and Chinese competitors were branded drug cheats by their U.S. and Australian rivals.

The IOC called on sports federations to modify the Beijing results that were affects and consider any other steps they felt appropriate.

idr (Reuters/AFP)