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.

Belarus had been ordered to return Ostapchuk's gold medal which would now be awarded to New Zealand's Valerie Adams, it added.

Russian Evgeniia Kolodko would move up to silver and China's Gong Lijiao would get bronze.

Ostapchuk, who had won the gold with a throw of 21.36 metres, was world champion in 2005 and European champion two years ago. In July, at a meeting in Minsk, she threw 21.58, the best outdoor distance in the world since 1998.

Adams said she was delighted to be promoted to gold.

"I am speechless with this news. It is taking me some time to take this in," she said in a statement.

"It is also encouraging for those athletes like myself, who are proud to compete cleanly, that the system works and doping cheats are caught."

By the start of Sunday's final day of the Games, 11 other athletes had been excluded after testing positive for banned drugs.

(China Daily 08/14/2012 page23)