The U.S. Anti-Doping Agency has made formal allegations of doping violations against Lance Armstrong that could strip him of all seven of his Tour de France titles.
Armstrong received a letter Tuesday that said USADA alleges he possessed and used testosterone and blood-doping products while a member of the U.S. Postal racing team, beginning in 1998.
The Washington Post first reported the letter of notice Wednesday afternoon.
Under USADA procedures, Armstrong has 10 days to respond to the charges, after which an independent anti-doping review panel would look at the USADA evidence and decide whether formally to charge Armstrong with doping.
If he contests the charges, he is entitled to a "trial," where evidence would be presented and witnesses would testify under oath. It would be up to Armstrong whether the hearing is open to the public.
Armstrong denied the allegations Wednesday.
"These are the very same charges and the same witnesses that the Justice Department chose not to pursue after a two-year investigation," he said in a statement released on his website. "These charges are baseless, motivated by spite and advanced through testimony bought and paid for by promises of anonymity and immunity. ... USADA's malice, its methods, its star-chamber practices, and its decision to punish first and adjudicate later all are at odds with our ideals of fairness and fair play.
"I have never doped, and, unlike many of my accusers, I have competed as an endurance athlete for 25 years with no spike in performance, passed more than 500 drug tests and never failed one. That USADA ignores this fundamental distinction and charges me instead of the admitted dopers says far more about USADA, its lack of fairness and this vendetta than it does about my guilt or innocence. Any fair consideration of these allegations has and will continue to vindicate me."
As a result of the charges, the World Triathlon Corporation has suspended Armstrong, who recently resumed his career as a triathlete, pending resolution of the case.
On Thursday, Ironman France spokeswoman Delphine Vivet said Armstrong can no longer compete in the June 24 triathlon in Nice because of the USADA proceedings.
He is currently allowed to compete in non-WTC events.
USADA's letter to Armstrong also said the agency was bringing doping charges against Johan Bruyneel, manager of Armstrong's winning teams; team doctors Pedro Celaya and Luis Garcia del Moral; team trainer Pepe Marti; and consulting doctor Michele Ferrari.
The USADA letter doesn't cite specific examples of his doping, but says the charges are based on evidence gathered in an investigation of Armstrong's teams, including witnesses who aren't named in the letter.
According to USADA's letter, "numerous riders, team personnel and others will testify" they either saw Armstrong dope or heard him tell them he used EPO, blood transfusions, testosterone and cortisone from 1996 to 2005. Armstrong won the Tour de France every year from 1999 to 2005.
The letter also says blood collections obtained by cycling's governing body in 2009 and '10 are "fully consistent with blood manipulation including EPO use and/or blood transfusions." Armstrong came out of retirement to race in the Tour de France those two years.
"USADA only initiates matters supported by the evidence," USADA CEO Travis T. Tygart said in a statement Wednesday night. "We do not choose whether or not we do our job based on outside pressures, intimidation or for any reason other than the evidence. Our duty on behalf of clean athletes and those that value the integrity of sport is to fairly and thoroughly evaluate all the evidence available and when there is credible evidence of doping, take action under the established rules."
Cycling's governing body, the International Cycling Union, which collected the 2009 and 2010 samples cited in the USADA letter, said it was not involved in the anti-doping group's investigation.
The U.S. Attorney's office in Los Angeles announced earlier this year that it was dropping an investigation into an alleged doping scheme with the U.S. Postal team that could have resulted in conspiracy and fraud charges against Armstrong.
A lawyer familiar with the case said the government shared no information from its case with USADA.
More than 10 cyclists and team staff members who witnessed the alleged doping activity could be called to testify for USADA, according to the letter, which did not name them.
Armstrong's former teammate, Tyler Hamilton, who served a two-year doping suspension and is now retired, last year confessed to his own use of performance-enhancing drugs and techniques and said he had seen Armstrong do the same in an interview with "60 Minutes."
On Wednesday, he told ESPN.com that if USADA formally charges Armstrong, it would be "an important and necessary step for the sport of cycling.''
"I've said all along, it's not about Lance, but about the truth coming out about what was happening in cycling at that time,'' Hamilton said. "It's going to be difficult and painful for the sport, but it has to come out in order for cycling to move forward.''
Information from ESPN.com's Bonnie D. Ford and The Associated Press was used in this report.