Fire destroyed a small rural home near Whangarei leaving only charred piles and mangled corrugated roofing iron.
The owners of the house in Jackson Rd, Maungatapere, were not at home when the fire was reported about 8.30pm on Thursday.
Fire investigator Craig Bain was sifting through the remains in the rain yesterday to try and find what caused the blaze.
But, Mr Bain said, it was very difficult as there was so little left of the building and attached garage.
"It appears to have been a very intense fire," he said.
Firefighters from Whangarei station were called but the house was well involved in fire when they arrived and all the could do was dampen down the site.
A water tank near the house was showing signs of heat damage as the plastic had started to bubble and buckle.
It was believed the owners were away in Auckland and the house was being prepared for sale.
A neighbour had raised the alarm after seeing smoke.