The IOC is looking into the Olympic involvement of Armstrong, other riders and officials implicated in the U.S. Anti-Doping Agency report detailing "the most sophisticated, professionalized and successful doping program that sport has ever seen."

Cycling's governing body, the UCI, last week formally stripped Armstrong of his seven Tour de France titles from 1999-2005. Armstrong could also lose the bronze medal he won in the road time trial at the 2000 Sydney Olympics.

"The IOC will now immediately start the process concerning the involvement of Lance Armstrong, other riders and particularly their entourages with respect to the Olympic Games and their future involvement with the games," the International Olympic Committee said in a statement.

Levi Leipheimer, a former Armstrong teammate who won the time-trial bronze at the 2008 Beijing Games, could also have his medal revoked. One of the key witnesses in the USADA's case against Armstrong, Leipheimer confessed to doping.

The medals could come up for review at the IOC's executive board meeting next month in Lausanne, Switzerland. Meantime, the IOC is also monitoring the UCI's plans for an independent investigation to examine allegations about the federation's own conduct and relations with Armstrong raised by the USADA report.

"The IOC has taken note of the UCI's decision and welcomes all measures that will shed light on the full extent of this episode and allow the sport to reform and to move forward," the IOC said.

"We await the findings of the independent commission which will look into the UCI's role, and the recommendations they will make to ensure a healthy future for cycling."

In the case of Armstrong's medal, the IOC will have to study whether the eight-year statute for revising Olympic results applies or not.

IOC vice president Thomas Bach recently said that the USADA report took an "intriguing approach" that leaves the eight-year period open to discussion.

"What we would have to check is whether this would also work under Swiss law or whether we find a way to apply U.S. law," Bach said.

Armstrong finished behind winner and U.S. Postal Service teammate Vyacheslav Ekimov of Russia and Jan Ullrich of Germany. Fourth place went to Abraham Olano Manzano of Spain, who stands to move up to bronze if Armstrong is stripped of the medal.

Finishing fourth behind Leipheimer in 2008 was Alberto Contador, the Spaniard who was stripped of the 2010 Tour de France title after testing positive for clenbuterol.

Leipheimer is currently serving a reduced, six-month suspension after cooperating with the USADA probe. He was fired by the Belgium-based Quick Step team last week "in light of the disclosures."

In August, the IOC stripped Tyler Hamilton - a former Armstrong teammate - of his gold medal from the 2004 Athens Olympics after he admitted to doping. Former Armstrong teammate Ekimov was upgraded to the gold.