A man's corpse was found in two pieces Tuesday morning, his body strapped into the driver's seat of a rental car that had crashed into a gate post at a park in the city of Uozu, Toyama Prefecture, and his head on the floor at his feet, police said.
The car was spotted in a parking lot at Kyoden Kaihin Park by local residents at around 8 a.m. The engine of the vehicle was still running at the time.
An initial investigation indicated the deceased was in his 50s.
Police said they believe it is highly likely the case is a suicide and will conduct an autopsy to determine the specific cause of death.
A length of nylon rope was found tied to a pine tree about 10 meters from the car, and the window of the driver's seat was open. The way in which the head was severed indicated a sharp object was not used, police said.
Investigators said the circumstances suggest the man tied the rope around his neck, strapped himself in the seat and stepped on the gas, adding that local residents heard a noise like a crash at around 3 a.m.
No suicide note was found in the car, which bears Toyama license plates, police said.