A plane heading from Los Angeles to Tokyo turned back because an unauthorized person was on board.

KABC-TV reports All Nippon Airways Flight 175 left Los Angeles International Airport around 11:30 a.m. Tuesday, but it never arrived at Tokyo's Narita International Airport.

The flight made a U-turn about four hours into the 11-hour flight.

Model Chrissy Teigen, who was on the plane with her husband John Legend, live tweeted the whole ordeal to her 9.2 million followers.

"4 hours into an 11 hour flight and we are turning around because we have a passenger who isn't supposed to be on this plane. Why...why do we all gotta go back, I do not know," Teigen said.

Teigen said passengers were told that someone had managed to board the ANA flight with a United Airlines ticket.

The plane landed at LAX around 7:30 p.m. after eight hours in the air.

Teigen says police interviewed passengers who were sitting near the person.

Airport police tell KABC-TV that there was a "mix-up" thattarget="_blank"'>