Four medallists from the 2004 Olympic Games have been officially stripped of their medals by the International Olympic Committee (IOC).
The IOC took the decision after new analysis of their dope tests taken at the Athens Games revealed traces of steroids.
Ukraine's Yuri Belonog was stripped of his shot put gold medal, Belarus' Ivan Tikhon of his silver in the hammer, and Irina Yatchenko of Belarus and Russian Svetlana Krivelyova lost their bronze medals in the women's discus and shot put respectively.
It is the second Olympic medal Tikhon has been stripped of, having had his bronze from the 2008 Games taken away, also for a doping offence.
The IOC announced that Adam Nelson of the United States, silver medallist in the shot put, would be awarded gold, while Denmark's Joachim Olsen is awarded silver and Manuel Martinez of Spain the bronze. Turkey's Esref Apak is promoted from bronze to sliver medal in the hammer and Vadzim Dzevyatusky of Belarus takes bronze.
In the women's events, the discus and shot put bronze medals go respectively to Vera Pospisilova-Cechlova of the Czech Republic and Nadezhda Ostapchuk of Belarus.
Ironically Ostapchuk was disqualified earlier this year after winning gold in the shot put at the London Olympics for testing positive for the banned anabolic agent metenolone - she is serving a one-year ban.
There is a fifth medallist from the 2004 Games who is at risk of being disqualified, but whose name will be revealed later by the IOC because of a delay in the procedure of the athlete's test.
Since the Athens Games, all dope tests taken at the Olympics have been stored in a large deep freeze in the basement of the anti-doping laboratory in Lausanne for eight years.
The IOC had asked the laboratory to reanalyse 105 tests taken at the Games in Athens, which holds the unwanted record for the most failed dope tests in Olympic history.