The probe has been expected to center on the International Cycling Union's handling of doping in the late 1990s and early 2000s, especially its links with Armstrong. Armstrong's willingness to meet with investigators has been seen as crucial to their efforts to determine whether former officials with the sport's governing body aided his doping as the Texan became cycling's biggest star.
Armstrong won the Tour de France every year from 1999-2005. Those titles were stripped after a massive report by the U.S. Anti-Doping Agency detailed doping by Armstrong and his U.S. Postal Service teammates.
Peters declined to detail exactly who was in the room or what Armstrong told them, but said Armstrong met with three people "running" the Cycling Independent Reform Commission and their attorney. A spokesman for the group did not immediately return a call or text message seeking comment Thursday night.
The commission is chaired by Dick Marty, a Swiss politician and former Swiss state prosecutor. The other members are German anti-doping expert Ulrich Haas and Peter Nicholson, a former Australian military officer and war crimes investigator.
Armstrong had previously said he'd be willing to talk to the panel and Peters said Armstrong had him contact the commission to set up the meeting.
UCI President Brian Cookson has said in the past that Armstrong's lifetime ban for doping could be reduced if he provides information which assists other doping investigations. The panel has the authority to cut deals with cheaters who provide valuable information. But Peters said Armstrong did not ask for, and was not offered such a deal in exchange for meeting with the group.
"There is no agreement and that was never discussed. We never asked for one," Peters said. "We do think the ban was unfairly harsh and should be reduced.... He's talking in the spirit of not trying to benefit by getting somebody else in trouble, but in the spirit of let's tell the truth."
Armstrong's meeting with the CRIC was voluntary but he has been forced to testify under oath in lawsuits in Texas.
Last month, Armstrong was questioned in a private arbitration dispute with a Dallas company seeking repayment of $12 million in bonuses it paid him during his career.
In late 2013, Armstrong provided sworn written testimony in another lawsuit seeking repayment of other bonus awards. In that testimony, Armstrong named several people he says knew about his performance-enhancing drug use, but also insisted he didn't pay anyone or any organization to keep his doping secret.
Armstrong also is facing a federal whistleblower lawsuit filed by former teammate Floyd Landis. The government joined Landis' lawsuit and is seeking to recover about $40 million in U.S. Postal Service sponsorship money paid to Armstrong and his teams. Under the False Claims Act, penalties in the case could run as high as $100 million.
Armstrong has so far refused to provide sworn testimony to the U.S. Anti-Doping Agency. USADA has questioned whether Armstrong paid officials at the International Cycling Union to keep his doping secret.
Armstrong has said in interviews that former UCI president Hein Verbruggen helped him cover up doping at the 1999 Tour de France, a charge Verbruggen has denied. But Armstrong has denied he paid anyone or any organization to hide his doping.