According to Fox Sports, the league has interviewed him and has video.
The league is still gauging whether any wrongdoing occurred, but he is a strong person of interest, Fox Sports reported.
The location in question was a bathroom in which the attendant can be seen in the video entering and exiting in 90 seconds with the 24 footballs provided by both teams, according to Pro Football Talk, which cited an anonymous league source.
The bathroom is a small, one-toilet room with one sink and has a door that locks from the inside, the Pro Football Talk report said.
Meanwhile, Ted Wells, the investigator hired by the NFL, said Monday that he expects his investigation to last at least several more weeks.
"We are following customary investigative procedures and no one should draw any conclusions about the sequence of interviews or any other steps, all of which are part of the process of doing a thorough and fair investigation," Wells said in a statement.
In a news conference on Thursday that lasted a little more than 30 minutes, Patriots quarterback Tom Brady detailed how he selected 24 footballs for referees to inspect before Sunday's AFC Championship Game against the Indianapolis Colts and said he "didn't alter the ball in any way."
The NFL found that 11 of the Patriots' 12 game balls from their 45-7 win were inflated significantly below the NFL's requirements, league sources involved and familiar with the investigation of Sunday's game told ESPN's Chris Mortensen.
The NFL on Friday released a statement on their investigation, saying they had conducted nearly 40 interviews to that point. Patriots wide receiver Matthew Slater said Saturday that the NFL Players Association has advised Patriots playersnot to discuss the ongoing investigation.
Also on Saturday, Patriots coach Bill Belichick detailed the organization's preparation process and suggested that weather conditions may have affected the air pressure in the footballs. The longtime coach emotionally defended his team, saying, "We did everything as right as we can do it."
NFL Eyes Patriots Locker-Room Attendant
Chris Mortensen, Bill Polian and Adam Schefter have the latest on the NFL looking into a New England locker-room attendant who allegedly took game balls from the officials locker room to another area on the way to the field.
Officials' Protocol In Handling Game Balls
Former referee Jim Daopoulos discusses the officials locker-room area at Gillette Stadium and the protocol for handling game balls prior to the game.