Lance Armstrong was facing the prospect of losing his record-breaking total of seven Tour de France titles after the United States Anti-Doping Agency confirmed they had begun legal proceedings against the former cyclist.
The USADA revealed last night it had sent Armstrong written notification regarding "allegations of anti-doping rule violations" during his time with the United States Postal Service (USPS) cycling team.
The USADA confirmation came hours after Armstrong, 40, had released a statement of his own to angrily deny the claims, which, if proved, could see him stripped of the Tour titles he won while with USPS.
"I have been notified that USADA, an organisation largely funded by taxpayer dollars but governed only by self-written rules, intends to again dredge up discredited allegations dating back more than 16 years to prevent me from competing as a triathlete and try and strip me of the seven Tour de France victories I earned," Armstrong said.
"These are the very same charges and the same witnesses that the Justice Department chose not to pursue after a two-year investigation. These charges are baseless, motivated by spite and advanced through testimony bought and paid for by promises of anonymity and immunity.
"Although USADA alleges a wide-ranging conspiracy extended over more than 16 years, I am the only athlete it has chosen to charge. 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."
Following those comments the USADA released their own statement to confirm the charges, which immediately prevent Armstrong from competing as a triathlete - the sport he took up following his retirement from cycling in 2011.
"In response to numerous inquiries regarding the public statements made by Mr Lance Armstrong, we can confirm that written notice of allegations of anti-doping rule violations was sent yesterday to him and to five additional individuals all formerly associated with the United States Postal Service (USPS) professional cycling team," the statement said.
"These individuals include three team doctors and two team officials.
"This formal notice letter is the first step in the multi-step legal process for alleged sport anti-doping rule violations."
Armstrong survived testicular cancer early in his career and went on to win seven consecutive Tour de France titles from 1999 to 2005 while competing for the US Postal Service team and the Discovery Channel team.
He retired after the 2005 Tour de France, but returned in 2009, riding for Astana Cycling and RadioShack before retiring for a second time in February 2011, taking up triathlon earlier this year.