After Stowaway Found, Delta Investigates Flight From New York to Paris

Delta Air Lines said it had opened an investigation after the pilot of a flight that landed in Paris on Wednesday announced that the police were boarding his plane because it was carrying an extra passenger.

A representative for the U.S. Transportation Security Administration said on Wednesday that a person went through security screening but avoided identity and boarding pass checks before boarding a flight that left the United States. Without identifying the flight, the representative referred questions to the police at Charles de Gaulle Airport, which serves Paris.

In a statement, Delta said that it was working with law enforcement and aviation authorities to investigate Flight 264, the plane that was boarded in Paris. The flight departed Kennedy International Airport in New York on Tuesday night, landing at Charles de Gaulle the next day, according to flight trackers. Delta did not provide further details on what it was investigating.

The airport authorities in Paris said that they could not share information about the extra passenger.

Another passenger on Flight 264, Rob Jackson, said that he had been traveling to meet friends in France. The flight felt completely normal, he said, until the aircraft began descending into Paris, and he could hear the flight attendants’ intercoms going off repeatedly.

“I fly a lot, and it was unusual for that to be happening just as we were landing,” Mr. Jackson said.

When the plane arrived at the gate, the seatbelt signs remained on for longer than usual, he added. After the crew’s routine announcements welcoming the passengers to Paris, the captain shared some unexpected news.

“We’re just waiting for the police to come on board,” the captain can be heard saying in a video that Mr. Jackson recorded on the plane. “They’ve directed us to keep everyone on the airplane until we sort out an extra passenger that’s on the plane.”

Minutes later, Mr. Jackson said that he saw six or seven police officers enter the plane and that he subsequently overheard a flight attendant telling another crew member that a woman had been hopping from one lavatory to another throughout the flight, without ever going to a seat. The flight, which takes about seven hours, was full, Mr. Jackson added.

The plane remained parked at the gate for about 40 minutes, frustrating some passengers who had connecting flights, he said. He eventually heard other passengers saying, “She’s off.”

When asked about the incident, the Federal Bureau of Investigation referred questions to the Port Authority of New York and New Jersey, which operates Kennedy International, and to the Queens District Attorney’s office. Neither responded to requests for comment early Thursday.

Experts have warned that this Thanksgiving travel week in the United States will be the busiest ever. The T.S.A. said that it expected to screen 18.3 million travelers from Tuesday through Monday, which would be a 6 percent increase from last year.

Hank Sanders contributed reporting.