The chief fire officer of the Hampden Volunteer Fire Brigade arrived home on Tuesday night to find his house on fire.
A Fire and Emergency New Zealand spokesman said the Hampden, Palmerston and Weston brigades responded to the fire in Joyce Rd at 8.45pm.
Three fire engines and three water tankers attended.
The owner arrived home to find his house burning, the spokesman said.
Nobody was in the house during the blaze, but the building was extensively damaged.
Fenz confirmed the house was owned by a member of the volunteer fire brigade, and it is understood it was Chief Fire Officer Shane Trimble.
Fire risk management officer Mark Bredenbeck said he had narrowed the source of the fire down to three possible causes.
Due to the close proximity of the possible causes it was likely the exact cause would never be found.
Mr Trimble declined to comment on the incident.
