The Associated Press and USA Today are reportinghas confessed to doping.
On Monday, he had apologized to the staff of the multi-million dollar charity, Livestrong, that he had created.
Later in the day he gave an interview toadmitting he used drugs to win all those Tour de France titles.
The interview will be conducted in Armstrong’s hometown of Austin, Texas, and will be telecast Thursday on Oprah's network.
Anti-drug authorities and executives of the Tour de France have already stripped the 41-year-old of his seven titles. Critics say he threatened anyone who would expose his doping.
He was forced to step down from the board of the charity he founded after a large file on his doping was released by anti-doping officials in October.
He is apparently outside the statute of limitations now on any charges he might face, and can only get back into racing by admitting his guilt and throwing himself on the mercy of cycling officials. A federal investigation last year ended with no charges being filed.
Media reports have estimated that he is still worth $100 million even after losing all his endorsements.
His was the story of a lifetime: survivor of testicular cancer comes back and becomes world cycling champion.
The Radar Online Website said former fiancée helped in the investigation.
The US Anti-Doping Agency had battled with Armstrong, unable to catch him with a banned substance in his blood. The agency called it “the most sophisticated, professionalized and successful doping program that sport has ever seen.” USADA chief executive Travis Tygart labeled said Armstrong led an effort by his US Postal Service team resulted in the domination of the world’s premier cycling event, the Tour de France, by his team.
USA Today quoted Livestrong spokesman Katherine McLane as saying it was a "very sincere and heartfelt apology to the staff."
Armstrong’s denials were so believable he won a $500,000 lawsuit against Rupert Murdoch’s London Sunday Times.
But former teammatefiled a lawsuit accusing Armstrong of defrauding the US Postal Service. Landis admitted doping, was stripped of the 2006 Tour de France title and said he witnessed Armstrong using illegal drugs and was encouraged by him to do the same.
Armstrong is likely to face several lawsuits, possibly from sponsors, as well as the Sunday Times.
The Associated Press story said although if rules are strictly interpreted the lifetime ban on Armstrong could only be ended after eight years, the agency could be flexible if Armstrong helps in their investigation on how the cheating was done. USADA officials told AP it could become a “pathway to redemption.”