The much anticipated airing of disgraced cyclist Lance Armstrong's interview with Oprah Winfrey began broadcast at 9 p.m. ET (0200 GMT) on the talk show host's cable network OWN.
In the two-part interview, also being streamed live online to a global audience, cancer survivor Armstrong is expected to confess to using performance-enhancing drugs during a career in which he won the Tour de France seven times.
Armstrong's world began to crumble in October last year when the U.S. Anti-Doping Agency released a detailed report with sworn testimony from dozens of people that described him as the ringmaster of the "most sophisticated, professionalized and successful doping program that sport has ever seen."
Armstrong had always denied the accusations made against him, which involved the use of anabolic steroids, human growth hormone, blood transfusions and other doping.
Already banned for life and stripped of all his race wins, including his Tour titles, Armstrong could face the prospect of jail time and the repayment of millions of dollars in sponsorship and earnings.