The International Olympic Committee (IOC) on Thursday asked disgraced American cyclist Lance Armstrong to return the Olympic bronze medal from the time-trial event at the 2000 Games in Sydney.
The IOC had written to Armstrong late on Wednesday to ask him hand back the medal, IOC spokesman Mark Adams told AFP.
The IOC had to wait for world cycling's governing body to sanction Armstrong, which it did on December 6, and the following three weeks in which the Texan had recourse to appeal at the Court of Arbitration for Sport (CAS).
The US Olympic Committee, to which Armstrong must theoretically return the medal, has also been informed, Adams added.
Armstrong was stripped of his seven Tour de France titles and banned from the sport for life in October after the US Anti-Doping Agency (USADA) produced evidence of widespread doping by him and his former team-mates.
The time-trial in the 2000 Games was won by Armstrong's ex-US Postal Service teammate Viasheslav Ekimov of Russia, now general manager of the Katusha team whose ambivalent stance on doping cost them a place in the elite ProTeam list for this season.
The silver medal went to one of Armstrong's great rivals, Jan Ullrich of Germany, who was caught up in the Operation Puerto doping probe and eventually served a two-year ban for doping.
Abraham Olano of Spain came home in fourth and may be set to inherit the bronze vacated by Armstrong.
Other notable results in the race held in Sydney were by American Tyler Hamilton, a former teammate of Armstrong at US Postal who finished tenth and went on to win gold at the 2004 Athens Games before testing positive for doping.
British rider David Millar finished 16th and is still currently on the circuit after serving his own two-year ban from 2004.
The International Cycling Union (UCI) late last year effectively erased Armstrong from the cycling history books when it decided not to appeal sanctions imposed on the Texan rider by the USADA.
In his first interview since Armstrong was shorn of his Tour titles, recorded Monday with Oprah Winfrey and due to be broadcast on Thursday and Friday, the chat show host confirmed that the Texan admitted using performance-enhancing drugs.