Lance Armstrong faces charges from the US Anti-Doping Agency (USADA) over allegations dating back to 2008.
The watchdog informed the seven-time Tour de France winner that they plan to revive their investigation, which was shelved in 2011.
Armstrong could be stripped of his Tour de France titles if found guilty, and banned from competing as a triathlete.
In a statement issued this evening (June 13), the athlete denied the allegations and accused the USADA of pursing a vendetta against him.
"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," he 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."
Armstrong, a survivor of testicular cancer, retired for a second time in 2011 before taking up triathlon.