A minicar broke through a security checkpoint at Narita airport on Tuesday afternoon and drove onto the airport grounds, police said.
All automobile gates at the airport were shut down for about 40 minutes, but police were unable to locate the silver car.
A vehicle believed to be the minicar was found later in the day on an expressway in Kawasaki, and police said they were questioning a man found walking along the highway.
Flights were unaffected by the security breach, according to the airport operator, Narita International Airport Corp.
The car, believed to have been driven by a man traveling alone, entered at the airport's No. 2 gate, an entrance for public vehicles. It broke through the plastic security gate and drove off in the direction of the Terminal 2 building at around 1:20 p.m., according to the police.
Last November a 34-year-old man broke through a checkpoint at the airport in a car and fatally stabbed a police officer who had pursued him to Sakura, Chiba Prefecture.