U.S. Anti-Doping Agency Chief Executive Officer Travis Tygart said the organization was sending a "Reasoned Decision" regarding Armstrong to international, cycling, doping and triathlon groups charging that Armstrong used performance-enhancing drugs while a member of the U.S. Postal Service-sponsored cycling team.
A release from Tygart stated more than 1,000 pages of documentation would be posted on the USADA website. The agency said 26 people including 15 cyclists, testified about the USPS team's doping activities.
"The evidence shows beyond any doubt that the U.S. Postal Service Pro Cycling Team ran the most sophisticated, professionalized and successful doping program that sport has ever seen," Tygart said in the release.
The statement said collected evidence included witness testimony, documentary, first-hand, scientific, direct and circumstantial evidence."
""(The combined evidence) reveal conclusive and undeniable proof that brings to the light of day for the first time this systemic, sustained and highly professionalized team-run doping conspiracy," the release said.
"The USPS Team doping conspiracy was professionally designed to groom and pressure athletes to use dangerous drugs, to evade detection, to ensure its secrecy and ultimately gain an unfair competitive advantage through superior doping practices. A program organized by individuals who thought they were above the rules and who still play a major and active role in sport today."
Armstrong has consistently denied the use of performance-enhancing drugs, saying he passed every drug test administered.
Armstrong won overall Tour de France titles seven times from 1999-2005. The USADA release said Armstrong accepted the "disqualification of his competitive results from 1998 forward" when he dropped legal actions against the USADA in August.
Armstrong had no immediate comment on the USADA report.