AUSTIN, Texas (CBS NEWS) -- Lance Armstrong confessed to Oprah Winfrey during an interview Monday that he used performance-enhancing drugs to win the Tour de France, Winfrey confirmed Tuesday.

The admission -- made in an interview to be broadcast in two separate installments starting Thursday on Winfrey's network -- was confirmed by CBS News Monday. Winfrey appeared on "CBS This Morning" on Tuesday to talk about the Armstrong interview, saying that both parties had agreed not to speak publicly about it until the interview aired, but "by the time I left Austin and landed in Chicago you all had already confirmed it." 

Winfrey described Armstrong as "forthcoming" in the interview and while he "did not come clean in the manner that I expected," she said she was "satisfied by the answers."

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

Just hours before the revelation, Armstrong appeared at the cancer charity he founded and tearfully apologized to the Livestrong charity that he founded and turned into a global institution on the strength of his celebrity as a cancer survivor.

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

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.

Winfrey and her crew had earlier said they would film the interview at his home but the location apparently changed to a hotel. Local and international news crews staked out positions in front of the cyclist's Spanish-style villa before dawn, hoping to catch a glimpse of Winfrey or Armstrong.

Armstrong still managed to slip away for a run Monday morning despite the crowds gathering outside his house. He returned home by cutting through a neighbor's yard and hopping a fence.

During a jog on Sunday, Armstrong talked to the AP for a few minutes saying, "I'm calm, I'm at ease and ready to speak candidly." He declined to go into specifics.

Armstrong lost all seven Tour titles following a voluminous U.S. Anti-Doping Agency report that portrayed him as a ruthless competitor, willing to go to any lengths to win the prestigious race.

USADA chief executive Travis Tygart labeled the doping regimen allegedly carried out by the U.S. Postal Service team that Armstrong once led, "The most sophisticated, professionalized and successful doping program that sport has ever seen."

In a recent "60 Minutes Sports" interview, Tygart described Armstrong and his team of doctors, coaches and riders as similar to a "Mafia" that kept their secret for years and intimidated riders into silently following their illegal methods.

Yet Armstrong looked like just another runner getting in his roadwork when he talked to the AP, wearing a red jersey and black shorts, sunglasses and a white baseball cap pulled down to his eyes. Leaning into a reporter's car on the shoulder of a busy Austin road, he seemed unfazed by the attention and the news crews that made stops at his home. He cracked a few jokes about all the reporters vying for his attention, then added, "but now I want to finish my run," and took off down the road.

Meanwhile, Armstrong is in talks to return a portion of the millions of dollars in taxpayer money his former team, U.S. Postal Service, once received, CBS News has learned.

Senior Justice Department officials have recommended that the government join a lawsuit filed by one of Armstrong's former teammates that accuses the disgraced cyclist of defrauding the federal government. Armstrong's U.S. Postal sponsorship prohibited illegal doping.

CBS News has also learned Armstrong has indicated he may be willing to testify against others involved in illegal doping.

Once all the information was out and his reputation shattered, Armstrong defiantly tweeted a picture of himself on a couch at home with all seven of the yellow leader's jerseys on display in frames behind him. But the preponderance of evidence in the USADA report and pending legal challenges on several fronts apparently forced him to change tactics after more a decade of denials.

He still faces legal problems.

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.

The London-based Sunday Times also is suing Armstrong to recover about $500,000 it paid him to settle a libel lawsuit. On Sunday, the newspaper took out a full-page ad in the Chicago Tribune, offering Winfrey suggestions for what questions to ask Armstrong. 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.

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.

Many of his sponsors dropped Armstrong after the damning USADA report - at the cost of tens of millions of dollars - and soon after, he left the board of Livestrong, which he founded in 1997. Armstrong is still said to be worth about $100 million.

Livestrong might be one reason Armstrong has decided to come forward with an apology and limited confession. The charity supports cancer patients and still faces an image problem because of its association with Armstrong. He also may be hoping a confession would allow him to return to competition 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.