Human remains were found after a house burned down in East Nannup last night, 280km south of Perth.
Volunteer firefighters were called to a property on Gold Gully Road just before 5pm.
Paramedics received a call from a neighbour, who said the house was on fire and a male occupant was unaccounted for.
"Nannup Police and fire fighters attended the address," a police spokesman said.
The timber-framed house could not be saved.
Firefighters discovered remains among the rubble just after 8pm.
"Arson Squad detectives were called and they attended the scene overnight to conduct an examination of the property, and confirmed the remains located are that of a person," the police spokesman said.
"The deceased person has not been identified at this time, and a report will be prepared for the Coroner."
The deceased man is believed to be in his sixties.
Arson Squad officers have confirmed the cause of the fire is undetermined but it is not being treated as suspicious.
Anyone with information about the fire is asked to call Crime Stoppers on 1800 333 000.