Access to the fire was difficult because the house was surrounded by dense vegetation and piles of building materials and other items.
Firefighters, including eight wearing breathing apparatus, attacked the fire from both sides of the house, stopped the flames spreading to a neighbouring home, and continued searching for the missing men.
Both turned up later that evening, having been out when the fire started. Two homes downwind of the fire were evacuated and Foreshore Rd was closed to traffic, Mr Ross said.
At the peak more than 30 firefighters were at the scene with fire appliances, tankers and support vehicles from Ahipara, Kaitaia, Kerikeri, Houhora, Broadwood and Whangārei.
Of the two two-bedroom, bach-like dwellings on the property, one was still standing but unstable and completely gutted. One end of the other dwelling had been damaged and the rest saved.
''The Kaitaia and Ahipara crews did a thorough job of fighting the fire and searching for the missing men. They were absolutely outstanding,'' he said.
Fire safety officer Craig Bain said it appeared one of the occupants had lit a fire to heat an outdoor bath but the strong southwesterly wind had blown embers under the house where they ignited stored building materials.
He had contacted the Far North District Council about the danger posed by what was left of the house.
Overgrown vegetation had allowed the fire to spread towards neighbouring properties while a large number of items scattered around the property posed a hazard to firefighters working in the dark.
The cause of the April 22 fire on Foreshore Rd was an electrical fault in the meter board.
Acting Detective Sergeant Richard Garton, of Kaitaia police, agreed the fire appeared to have been an accident, but he had a few more people to talk to before the investigation was complete.