Olympic shot put gold medal winner Nadzeya Ostapchuk has been stripped of her title after failing a doping test, the International Olympic Committee has confirmed.
The Belarus athlete tested positive for anabolic agent metenolone during in-competition testing on 5 and 6 August and has been disqualified from the final results.
The gold medal is instead awarded to Valerie Adams of New Zealand, with Russia's Evgeniia Kolodko now taking silver and Lijiao Gong of China elevated to bronze.
An IOC statement read: "The International Olympic Committee (IOC) today announced that it has disqualified, withdrawn the medal from, and excluded Belarus's Nadzeya Ostapchuk (athletics, women's shot put) from the Games of the XXX Olympiad in London.
"The athlete was first requested to provide a urine sample for a doping control on 5 August. She competed the next day in the women's shot put event, where she placed first, and was asked to provide a sample straight after her competition.
"Both samples indicated the presence of metenolone, which is classified as anabolic agent under the 2012 Prohibited List."
Ostapchuk, 31, was competing in her third Olympic Games in London, having finished fourth in Athens in 2004 and claimed bronze in Beijing four years ago.
Ostapchuk threw 21.36m with her third attempt to win last week's shot put competition comfortably from Adams (20.70m).