“There is a lot of what we could have done better, but that’s easy to say 25 years later,” he said. “And there is a lot of criticism of me; I was a dictator and was too close to Armstrong. They had obviously come up with something.”

Mr. McQuaid did not respond to requests for comment.

Two of the three members of the commission, selected by Brian Cookson, the current cycling union president, have investigative backgrounds. Dick Marty, the leader of the commission, is a Swiss politician and former prosecutor who investigated the illegal trafficking of human organs in Kosovo and led Europe’s investigation into secret Central Intelligence Agency prisons. Another commission member, Peter Nicholson, a former Australian Army officer, conducted war crimes investigations for the United Nations.

The third member, Ulrich Haas, is a German professor specializing in antidoping laws and regulations.

For Mr. Armstrong, the report provides a small amount of vindication. While the commissioners did find that Mr. Armstrong’s special position had kept him from serious scrutiny and led to cover-ups, they did not conclude that donations he had made to U.C.I. were bribes, although they chastised U.C.I. for accepting them. The commission also rejected allegations that Mr. Armstrong had tested positive during the Tour of Switzerland and then successfully covered up. It did, however, find that he had suspicious test results at that race and was given special treatment afterward.

The commission also found that Mr. Armstrong’s doping practices had not differed from those of many of his rivals. But it added, “All of this is of course no excuse or justification for Lance Armstrong’s behavior, and there cannot be a shadow of a doubt that such behavior warrants a harsh sanction.”

Largely through internal cycling union documents, the commission pieced together an exceptional whitewashing involving Mr. Armstrong. In 2005, L’Equipe, the French daily sports newspaper that is part of the same corporation as the Tour de France, reported that Mr. Armstrong had tested positive for EPO during the 1999 Tour. Because the results came from retesting the old samples to verify an improved test for the hormone, they could not be used to penalize Mr. Armstrong.