AUSTIN, Texas -- After a decade of denial, Lance Armstrong has finally come clean: He used performance-enhancing drugs to win the Tour de France.

The disgraced cyclist made the confession to Oprah Winfrey during an interview taped Monday, a person familiar with the situation told The Associated Press. The person spoke on condition of anonymity because the interview is to be broadcast Thursday on Winfrey's network.

The admission Monday came hours after an emotional apology by Armstrong to the Livestrong charity that he founded and took global on the strength of his celebrity as a cancer survivor who came back to win one of sport's most grueling events.

A source told ABC News that Armstrong is also talking to cycling authorities about naming names of others involved in illegal doping in hopes of reducing his lifetime ban.

The confession to Winfrey was a stunning reversal, after years of public statements, interviews and court battles in which he denied doping and zealously protected his reputation.

Winfrey tweeted afterward, "Just wrapped with @lancearmstrong More than 2½ hours. He came READY!" She was scheduled to appear on "CBS This Morning" on Tuesday to discuss the interview.

Even before the taping session with Winfrey began around 2 p.m. ET, Armstrong's apology suggested he would carry through on promises over the weekend to answer her questions "directly, honestly and candidly."

USA Today, citing an anonymous source, reported Monday that Armstrong told Winfrey he began using performance-enhancing drugs in the mid-1990s, before he was diagnosed with cancer.

The cyclist was stripped of his Tour de France titles, lost most of his endorsements and was forced to leave the foundation last year after the U.S. Anti-Doping Agency issued a damning, 1,000-page report that accused him of masterminding a long-running doping scheme.

About 100 staff members of the charity Armstrong founded in 1997 gathered in a conference room as Armstrong arrived with a simple message: "I'm sorry." He choked up during a 20-minute talk, expressing regret for the long-running controversy tied to performance-enhancers had caused, but stopped short of admitting he used them.

Before he was done, several members were in tears when he urged them to continue the charity's mission, helping cancer patients and their families.

"Heartfelt and sincere," is how Livestrong spokesman Katherine McLane described his speech.

Armstrong later huddled with almost a dozen people before stepping into a room set up at a downtown Austin hotel for the interview.

The group included close friends and advisers, two of his lawyers and Bill Stapleton, his agent, manager and business partner. They exchanged handshakes and smiles but declined comment when approached by a reporter. Most members of that group left the hotel through the front entrance around 5 p.m., although Armstrong was not with them.

No further details about the interview were available immediately because of confidentiality agreements signed by both camps. But Winfrey promoted it as a "no-holds barred" session, and after the voluminous USADA report -- which included testimony from 11 former teammates -- she had plenty of material for questions. USADA chief executive Travis Tygart, a longtime critic of Armstrong's, called the drug regimen practiced while Armstrong led the U.S. Postal Service team, "The most sophisticated, professionalized and successful doping program that sport has ever seen."

Armstrong also went after his critics ruthlessly during his reign as cycling champion. He scolded some in public and didn't hesitate to punish outspoken riders during the race itself. He waged legal battles against still others in court.

Betsy Andreu, the wife of former Armstrong teammate Frankie Andreu, was one of the first to publicly accuse Armstrong of using performance-enhancing drugs. She called news of Armstrong's confession "very emotional and very sad," and got choked up as well when asked to comment.

"He used to be one of my husband's best friends and because he wouldn't go along with the doping, he got kicked to the side. Lance could have a positive impact if he tells the truth on everything. He's got to be completely honest," she said.

At least one of his opponents, the London-based Sunday Times, has already filed a lawsuit to recover about $500,000 it paid him to settle a libel case, and Dallas-based SCA Promotions, which tried to deny Armstrong a promised bonus for a Tour de France win, has threatened to bring yet another lawsuit seeking to recover more than $7.5 million an arbitration panel awarded the cyclist in that dispute.

In addition, former teammate Floyd Landis, who was stripped of the 2006 Tour de France title for doping, has filed a federal whistle-blower lawsuit that accused Armstrong of defrauding the U.S. Postal Service. The Justice Department has yet to decide whether it will join the suit as a plaintiff.

Armstrong is talking with authorities about paying back some of the money paid by the Postal Service for sponsoring his team, a source told ABC News.

The government of South Australia state also says it will seek damages or compensation from Armstrong. South Australia Premier Jay Weatherill said Tuesday the state would 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.

Weatherill said Armstrong's reported confession changed the government's view on its entitlement to compensation. He said Armstrong "has deceived the cycling community around the world" by repeatedly denying he used performance-enhancing drugs.

The lawsuit most likely to be influenced by a confession might be the Sunday Times case. Potential perjury charges stemming from Armstrong's sworn testimony in the 2005 arbitration fight would not apply because of the statute of limitations. Armstrong was not deposed during the federal investigation that was closed last year.

Armstrong is said to be worth around $100 million. But most sponsors dropped him after USADA's scathing report -- at the cost of tens of millions of dollars -- and soon after, he left the board of Livestrong.

After the USADA findings, he was also barred from competing in the elite triathlon or running events he participated in after his cycling career. World Anti-Doping Code rules state his lifetime ban cannot be reduced to less than eight years. WADA and U.S. Anti-Doping officials could agree to reduce the ban further depending on what information Armstrong provides and his level of cooperation.

On Tuesday, The International Cycling Union, or UCI, urged Armstrong to testify before its independent commission on doping.

The federation said "if these reports are true, we would strongly urge Lance Armstrong to testify to the independent commission established to investigate the allegations made against the UCI in the recent USADA reasoned decision on Lance Armstrong and the United States Postal Service team."

The UCI recently set up an independent panel to look into claims that it covered up suspicious samples from Armstrong, accepted financial donations from him and helped him avoid detection in doping tests.

Whether Armstrong's confession would begin to heal ruptures and restore that reputation remains to be seen.

Diagnosed with testicular cancer in October 1996, the disease soon spread to his lungs and brain. Armstrong's doctors gave him a 40 percent chance of survival at the time and never expected he'd compete at anything more strenuous than gin rummy. Winning the demanding race less than three years later made Armstrong a hero.

Information from The Associated Press was used in this report.