The IOC acted after the International Cycling Union (UCI) disqualified all of Armstrong's results as a consequence of the American rider being found guilty of systematic doping.

Armstrong had 21 days to appeal against the UCI's decision and once it was confirmed he had not done so, the IOC took action.

An IOC spokesman said: "We have written to Armstrong asking for him to return the medal and informed the US Olympic Committee.

"It was a decision taken in principle at the executive board before Christmas. We were waiting for confirmation from the UCI that he hadn't appealed against his disqualification."