(CNN) Chrissy Teigen and other Tokyo-bound passengers ended up right where they started after eight hours of flying: Los Angeles.
The model and TV personality tweeted about enduring her "flight to nowhere" Tuesday night after All Nippon Airways Flight 175 made a U-turn and headed back to Los Angeles.
The plane, which had 226 passengers aboard, turned around four hours into its flight to Tokyo "due to an administrative mix-up," an aviation source said.
The crew discovered an unauthorized passenger had boarded the flight, and opted to return to Los Angeles even though the mix-up was resolved, according to the source.
Two brothers were both going to Tokyo but were booked on separate flights, two law enforcement sources told CNN. One law enforcement source told CNN the two brothers have very similar names. Somehow, both brothers were allowed to board the All Nippon Airlines flight, even though only one of the brothers was actually booked on it. The crew discovered that extra person during the flight.
ANA told CNN the plane returned to Los Angeles as part of the airline's security procedure after someone boarded the wrong flight.
"The cabin crew notified the pilot that one of the passengers boarded the incorrect flight, and the pilot in command made the decision to return to the originating airport," the airline said in a statement.
An investigation is underway to determine how the passenger boarded the flight.
"We take great pride providing exemplary customer service, and on this flight we failed to do so," it said. The airline tweeted an apology to passengers.
The plane left Los Angeles International Airport at 11:36 a.m. (2:36 p.m. ET) Tuesday and returned at 7:33 p.m., according to the airline.
Teigen, who was aboard the flight with her husband, singer John Legend, tweeted the details of the ordeal as it unfolded.
"A flying first for me: 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," she tweeted. "Why ... why do we all gotta go back, I do not know."
As the flight returned to Los Angeles, Teigen made her questions known.
"Why did we all get punished for this one person's mistake? Why not just land in Tokyo and send the other person back? How is this the better idea, you ask? We all have the same questions."
Teigen later tweeted that passengers were questioned after they returned to Los Angeles.
"They put our plane in a secure area. We can't be near the common folk," she said.
The model kept her sense of humor as she answered questions about the incident.
"I don't know why I'm not more upset about this," she tweeted. "The pleasure I get out of the story is worth more to me than a direct flight to Tokyo."