Ray Rice told NFL commissioner Roger Goodell during a disciplinary hearing in June that he punched his then-fiancee, Janay Palmer, Feb. 15 in the elevator of an Atlantic City casino, according to a report. That account contradicts Goodell's contention during a television interview Tuesday that the former Ravens running back and his representatives offered an "ambiguous'' description of what had happened.

ESPN's "Outside the Lines'' reported Thursday that four sources said Rice told Goodell he had punched Palmer, which resulted in her being knocked unconscious at Revel Casino Hotel.

Goodell said the video released Monday by TMZ Sports was "inconsistent'' with what Rice told him during the hearing. Hours after the video was released, Goodell changed the terms of Rice's suspension from two games to indefinite.

"Ray didn't lie to the commissioner,'' a source with knowledge of the meeting told "Outside The Lines.'' "He told the full truth to Goodell. He made it clear he had hit her, and he told Goodell he was sorry and that it wouldn't happen again.''

Rice's account of the hearing likely will be included in the investigation of the NFL's handling of his situation. Goodell appointed former FBI director Robert Mueller late Wednesday night to investigate the matter.

Two NFL owners overseeing the probe said Thursday they have been assured it will be thorough and independent, with the findings to be made public upon its conclusion.

"Our sole motive here is to get the truth and then share Mr. Mueller's finding with the public,'' Giants president and co-owner John Mara and Steelers president and co-owner Art Rooney said in a joint statement.

Ravens general manager Ozzie Newsome, who attended the June 16 hearing, told the Baltimore Sun in Wednesday's editions that Rice did not lie about what had happened. Although Goodell never said Rice lied at the hearing, he did say Rice's comments "were not consistent with what was on that video. And when we saw that video, it was clear what happened.''

Goodell declined an interview request on Thursday night's CBS broadcast of the Steelers-Ravens game in Baltimore.

Ravens owner Steve Bisciotti said on CBS Thursday that his team made several attempts to get the video of Rice knocking out Palmer.

"We knew there was other video and our security did the steps that they normally would,'' Bisciotti told James Brown of CBS. "They called the casino and they would not release it. They called the Jets and the Giants and said, 'Do you have any influence, is there any way that you can help us?' They called back and said, 'No, that they would not release it.'

"The prosecutor said yesterday that would have been illegal. If I had said to Ray and his attorney, 'I can't keep you on this team until I see that tape,' I would have seen the tape and I would have sent it to Roger and said, 'You have to look at this tape before you render your decision.' ''

Mara and Rooney said the investigation will begin immediately, with no time constraints. It was announced late Wednesday, hours after an Associated Press report that an NFL employee received a DVD April 9 showing Rice striking Palmer in the face as they argued in the elevator.

In their statement, Mara and Rooney said: "We agreed the scope of the investigation should be aimed at getting answers to specific questions, including what efforts were made by league staff to obtain the video of what took place inside the elevator and to determine whether [it] was ever delivered to someone at the league office, and if so, what happened to the video after it was delivered.''

A bipartisan group of 16 female U.S. senators Thursday sent a letter to Goodell that was critical of the NFL's recently revised policy on domestic violence that increased a first offense to a six-game suspension.

"It is long past time for the NFL to institute a real zero-tolerance policy and send a strong message that the league will not tolerate violence against women by its players, who are role models for children across America.''