Nadzeya Ostapchuk of Belarus is the first athlete of the 2012 London Olympics to lose her medal for doping. Ostapchuk was the 8th athlete of the 2012 games to test positive, but the first medalist. From ESPN:

The International Olympic Committee said Ostapchuk, a former world champion, tested positive for steroids both before and after winning the shot put last week for her first Olympic gold.

Before and after. That’s some lazy doping right there. New Zealand’s Valerie Adams steps up from silver to gold with Ostapchuk’s dismissal. Evgeniia Kolodko of Russia moves up to the silver medal and China’s Gong Lijiao gets the bronze. [ESPN]