The couple's actions emerged in a surveillance video released Thursday by the office of Sen. Frank Lautenberg, D-N.J., who had pushed the Transportation Security Administration to release the footage.
In the video, the man stations himself near an exit lane, where departing passengers pass a security guard to leave the terminal. The security officer appears to walk over and tell the man to step outside a rope barrier.
A minute or so later, after the guard leaves his podium for several seconds, the woman approaches the exit from inside the terminal and motions to the man, who ducks under the rope to join her. The two then walk into the passenger-only area with their arms wrapped around each other.
During the time the guard was away from his post, dozens of passengers are seen walking out through the exit lane, further obscuring the man and woman. Someone waiting for an arriving passenger notified the guard.
The officer has been placed on administrative leave while the TSA investigates the breach.
"The surveillance video from Newark Liberty Airport clearly shows that a TSA officer's actions led to the Sunday incident," the TSA said in a statement Thursday. "We will use this hard lesson to reinforce the sharp focus and tight discipline at all our stations across the country and ensure we maintain the public trust."
One of Newark's terminals was closed for six hours Sunday night, stranding thousands of passengers and wreaking havoc on flight schedules around the world for more than a day.
During a news conference at the airport Wednesday, Lautenberg and fellow Sen. Robert Menendez and Rep. Donald Payne, also of New Jersey, criticized the TSA for the actions of the guard and for the revelation that the security camera at the checkpoint was streaming live video but wasn't recording at the time of the incident.
That forced TSA officials to seek out footage from security cameras operated by Continental Airlines, which delayed the notification of law enforcement personnel on site for about an hour.
Another surveillance camera showed the man leaving by a separate exit about 20 minutes after he entered. He has not been identified or located, but TSA spokeswoman Ann Davis said he would face criminal charges if he is found.
Lautenberg wasn't immediately available for comment on the video Thursday, but said in a statement that "the release of this video will give law enforcement another tool to help find the person who breached the security gate at Newark Liberty Airport. I encourage this individual or anyone with knowledge of his identity to immediately contact law enforcement."