Following that incident, police were called twice more to disorder complaints, but each time those involved had dispersed before officers arrived.
Terry Baylis, a specialist fire investigator, said two people and one child lived at the address but no one had been in the house at the time of the blaze. Mrs Kennett said they were staying at an address in a nearby street.
One neighbour said early yesterday that her husband had heard running in the driveway, which prompted him to look outside.
"He heard running off, and they were really running. When he looked out the window, and his eyesight isn't that good, all he saw was glowing."
The woman also looked outside and said she saw the house had filled with flames.
"Fire was racing through the house," she said.
The neighbour said she had been worried because she didn't know whether the occupants were inside.
"At that stage if [they were] inside, there was nothing we could do."
Mr Baylis said the fire was believed to have started in the lounge. He thought the house would have to be removed because of the damage.
Mr Baylis said the investigation was carried out with great care because the house had been reduced to an unsafe condition. It had been equipped with working alarms, which would have been a critical factor if people had been inside at the time.
Mr Begbie said police wanted to hear from anyone who witnessed events in Smeaton Drive and Tauroa St from midnight to 4am. They would also like to hear from anyone with information about the fire or disorder incidents.
Anyone with information can call Whangarei Police on 09 430 4500 or, to remain anonymous, Crimestoppers on 0800 555 111.