"We don't know how it happened and we're obviously not happy about it," said Greg Aiello, the league's senior vice president of communications.
One theory that should be put to rest is that multiple copies of the tape had been disbursed from the office and into the hands of the league's competition committee.
"That absoutely didn't happen," Aiello said. "There were no authorized distribution of any copies of the tape from the league office."
Rich McKay, co-chairman of the competition committee, said that he did not receive a copy of the tape and to his knowledge, no other committee member received one, either. Two other committee members verified McKay's position.
Aiello did note that the videotape only revealed what already had been reported and ultimately what commissioner Roger Goodell acted upon when he disciplined the Patriots and coach Bill Belichick.
Still, said Aiello, "We're concerned about how it got out."
Television reporter Chris Mortensen covers the NFL for ESPN.