Russian hammer thrower Tatyana Lysenko has been stripped of her 2012 Olympic gold after a positive drugs retest.
The double world champion had already been banned for doping by the IAAF, athletics' governing body, in April.
The 33-year old previously tested positive in 2007 and served a two-year ban that saw her miss the 2007 World Championships and 2008 Olympic Games.
Lysenko, who now competes under her married name Beloborodova, faces a lifetime suspension from the sport.
"Re-analysis resulted in a positive test for the prohibited substance turinabol," a statement from the International Olympic Committee said.
Poland's Anita Wlodarczyk, the silver medallist at London 2012 and a nominee for female European athlete of the year, could now be promoted to gold, which she won at the Rio Olympics in August.