Oprah confirms Armstrong confession
She said the cyclist was "forthcoming" as she asked him in detail about doping allegations that followed him throughout his seven Tour de France victories.
Speaking on CBS This Morning in the US, Winfrey said she had not planned to address Armstrong's confession before the interview aired on her own network but, "by the time I left Austin and landed in Chicago, you all had already confirmed it."
Winfrey interviewed Armstrong at a hotel in Austin. The session was to be broadcast on Thursday but Winfrey said it will now run in two parts over two nights because there is so much material.
Armstrong won every Tour from 1999 to 2005, but each of those titles was stripped last year as the US Anti-Doping Agency released a massive report built around the testimony of former teammates. USADA accused Armstrong of masterminding a long-running and sophisticated doping operation on his teams.
The 41-year-old denied the charges for years, and fiercely attacked his critics. But after losing his titles and being abandoned by corporate sponsors, he has changed course. The confession was a stunning reversal for a proud athlete and celebrity.
The International Cycling Union, or UCI, said it was aware of the reports that Armstrong had confessed to Winfrey. The governing body for the sport urged Armstrong to tell his story to an independent commission it has set up to examine claims it covered up suspicious samples from the cyclist, accepted financial donations from him and helped him avoid detection in doping tests.
Winfrey has promoted her interview, one of the biggest for her OWN network since she launched it in 2011, as a "no-holds barred" session, and after the voluminous USADA report - which included testimony from 11 former teammates - she said she went into the session with 112 questions ready to go. Not all of them were asked, she said, but many were.
In Australia, the government of South Australia state said it will seek the repayment of several million dollars in appearance fees paid to Armstrong for competing in the Tour Down Under in 2009, 2010 and 2011.
"We'd be more than happy for Mr Armstrong to make any repayment of monies to us," South Australia premier Jay Weatherill said.