The International Olympic Committee (IOC) is proceeding with an investigation that could result in Lance Armstrong losing his Olympic bronze medal for doping.
The IOC says it will "immediately" look into the Olympic involvement of Armstrong, other riders and officials implicated in the U.S. Anti-Doping Agency report describing systematic doping in cycling.
Cycling's governing body last week formally stripped Armstrong of his seven Tour de France titles.
The IOC says it "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."
Armstrong won bronze in the time trial at the 2000 Sydney Olympics.
Also under scrutiny is Levi Leipheimer, who won the time-trial bronze at the 2008 Beijing Games and has admitted to doping.