NFL investigators are focused on a New England Patriots locker room attendant in the case of the underinflated footballs in the AFC Championship Game, according to Jay Glazer of FOX Sports.

The attendant allegedly took game balls from the officials’ locker room to another area on the way to the field before the contest, sources told Glazer.

The league’s investigators have interviewed the attendant and have video, Glazer’s sources said, and the league is trying to determine whether the attendant did anything wrong.

Led by league executive Jeff Pash and outside investigator Ted Wells, the NFL is trying to determine how 11 of 12 footballs used by the Patriots against the Indianapolis Colts were found to be underinflated at halftime of the AFC title game.

Patriots coach Bill Belichick and quarterback Tom Brady have said they do not know why the game balls were underinflated, although Belichick on Saturday said a study by his staff determined that “atmospheric conditions” likely were to blame.

The footballs were inflated to proper pressure at halftime, and the Patriots outscored the Colts 28-0 in the second half as they won 45-7 and advanced to the Super Bowl in Glendale, Ariz., where they will play the Seattle Seahawks on Sunday.