Disgraced cyclist Lance Armstrong has reportedly confessed to using performance enhancing drugs to win the Tour de France.
Armstrong's highly anticipated interview with former talk-show host Oprah Winfrey was pre-recorded at his Texas home a short time ago.
An unnamed source has told The Associated Press that Armstrong admitted to using drugs.
Winfrey took to Twitter afterwards to reveal only that Armstrong was 'ready' for the interview in which he had promised to be honest and speak candidly.
"Just wrapped with @lancearmstrong. More than 2 1/2 hours . He came READY!" she wrote.
VIDEO: Watch Lance Armstrong continually deny drug use
Reports of a confession follow revelations that Armstrong personally apologised to staff of his Livestrong cancer charity earlier today.
"Lance came to the Livestrong Foundation's headquarters today for a private conversation with our staff and offered a sincere and heartfelt apology for the stress they've endured because of him," Livestrong spokeswoman Rae Bazzarre told AFP.
She added that Armstrong -- a cancer survivor who founded the charity in 1997 -- urged Livestrong staffers "to keep up their great work fighting for people affected by cancer."
The disgraced cyclist reportedly choked up and several employees cried during the session.
Journalists staked out Armstrong's home in Austin ahead of his interview with Winfrey.
For years he has repeatedly denied taking performance enhancing drugs to win the Tour de France and other big cycling events.
Reporters, photographers and TV crews took up positions across the street from Armstrong's opulent Austin home, which is surrounded by a 2.4m stone wall.
The interview with Winfrey is to air on her OWN cable network on Friday. It will also be streamed on its website (www.own.tv).
It is Armstrong's first interview since he was stripped in October of his seven Tour de France titles after the US Anti-Doping Agency (USADA) said he helped orchestrate the most sophisticated doping program in sports history.
Any confession by Armstrong could have legal or financial ramifications, particularly among big-name corporate sponsors such as Nike that had loyally stood by him even as doping allegations grew.
Since the International Cycling Union effectively erased him from the record books, Britain's The Sunday Times has sued Armstrong for more than $1.6 million over a libel payment made to him in 2006.
It had paid Armstrong $450,000 to settle a libel case after publishing a story suggesting he may have cheated, and now wants that money plus interest and legal costs repaid.
On Sunday, the Sunday Times took out an ad in the Chicago Tribune newspaper setting out 10 questions that Winfrey, whose OWN media network is based in the Midwestern metropolis, should ask Armstrong.
"Is it your intention to return the prize money you earned from Sept. 1998 to July 2010?" read one question. "Did you sue the Sunday Times to shut us up?" went another.
A Texas insurance company has also threatened legal action to recoup millions of dollars in bonuses it paid him for multiple Tour victories.
Armstrong's years of dominance in the sport's greatest race raised cycling's profile in the United States to new heights.
It also gave the Texan -- diagnosed in 1996 with late-stage testicular cancer that had spread to his brain and lungs -- a unique platform to promote cancer awareness and research.
The Lance Armstrong Foundation has raised almost $500 million since its creation in 1997.
In the wake of the allegations, several top sponsors dumped Armstrong and on November 14 the Livestrong Foundation dropped his name from the non-profit organization he founded.