Olympic women's shot put champion Nadzeya Ostapchuk (pictured) has been stripped of the gold medal she won at the London Games a week ago after testing positive for a banned anabolic steroid.

Two urine samples taken from the Belarussian before and after her win last Monday tested positive for metenolone, the International Olympic Committee (IOC) said in a statement on Monday, the day after the Games ended.

"Ostapchuk ... is disqualified from the women's shot put event, where she had placed first (and) is excluded from the Games of the XXX Olympiad in London in 2012," the statement said.