Stowaway Travels on Flight From U.S., Officials Say

A stowaway avoided identity and boarding-pass checks and traveled on a plane that left the United States, federal officials said Wednesday. A Delta Air Lines pilot announced on a jet that had just flown from New York to Paris that an extra passenger was on the plane, and the airline said it was investigating the flight.

A representative for the Transportation Security Administration said a person went through security screening without incident but bypassed two identity and boarding-pass verification stations to board a plane. Without sharing any specifics about the flight or the person, the representative referred questions to the police at Charles de Gaulle Airport in Paris.

Delta said in a statement that it was working with law enforcement and aviation authorities to investigate Flight 264. The flight departed New York’s Kennedy International Airport 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 they could not share information about the passenger.

A passenger on Flight 264, Rob Jackson, was 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 said. 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 saw six or seven police officers enter the plane. He said he 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 the Queens District Attorney’s office. Neither responded to requests for comment early Thursday.

Tuesday was the start of what officials expect to be the busiest Thanksgiving travel week. 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.