The United States Anti-Doping Agency (USADA) labelled him a "serial" cheat who led "the most sophisticated, professionalised and successful doping programme that sport has ever seen".
Following evidence released on Wednesday from eleven of Lance Armstrong's former team-mates, USADA outlined the reasons behind their decision to strip the seven-time Tour de France winner of all his titles and hand him a lifetime ban.
According to USADA chief executive Travis T Tygart, there was "conclusive and undeniable proof" of a team-run doping conspiracy at Armstrong's US Postal Service Pro Cycling Team.
"USADA has found proof beyond a reasonable doubt that Lance Armstrong engaged in serial cheating through the use, administration and trafficking of performance-enhancing drugs and methods and that Armstrong participated in running in the US Postal Service Team as a doping conspiracy.
"Armstrong and his co-conspirators sought to achieve their ambitions through a massive fraud now more fully exposed. So ends one of the most sordid chapters in sports history."
Armstrong decided earlier this year not to contest the USADA charges, but he has always denied any involvement with doping and his lawyer Sean E Breen denounced the action as "a patently unfair, rigged process".
The former team-mates who gave evidence against Armstrong were Tyler Hamilton and Floyd Landis, Frankie Andreu, Michael Barry, Tom Danielson, George Hincapie, Levi Leipheimer, Stephen Swart, Christian Vande Velde, Jonathan Vaughters and David Zabriskie.
USADA claimed Armstrong, 41, supplied banned drugs to other riders on the team, pressured them into participating in the doping programme and threatened to get them removed from the team if they refused.
The document said: "His goal [of winning the Tour de France multiple times] led him to depend on EPO, testosterone and blood transfusions but also, more ruthlessly, to expect and to require that his team-mates would likewise use drugs to support his goals if not their own."
It added: "It was not enough that his team-mates give maximum effort on the bike, he also required that they adhere to the doping programme outlined for them or be replaced."
USADA claimed the evidence against Armstrong was "beyond strong" and stretched to more than 1,000 pages.