Detective Sergeant Beatson (phone (09) 408-6500) said he would be pleased to hear from anyone who saw anything suspicious, or had any other information that might help the inquiry.
Meanwhile two appliances were dispatched to the address next door moments after Mr Bain arrived to examine the garage, when smoke was seen rising from the roof of a flat. The owner of the property said his tenants were cooking chips, which turned out to be the case, the firefighters' only job being to use a blower to get rid of the smoke.
There was a better outcome at Herekino on Saturday night, where the occupants of a house extinguished a fire before the brigade arrived. Mr Bain said the fire started in a wall in the pantry, filling the house with smoke. The occupants had been awake when it started and no one was hurt, although significant damage was done.
Mr Bain added that it had not been difficult to determine the cause of the fire.
"Rodents and wiring don't mix," he said.