A suspicious fire which destroyed the upper level of an abandoned Kaipara dairy factory has sparked a reminder for owners to secure derelict buildings.
Ruawai fire services were alerted to the fire at 6.30pm on Tuesday. Crews from Dargaville, Ruawai, Maungaturoto, Whangarei and Paparoa also attended and had the blaze contained by 8.30pm.
Special fire investigator Craig Bain said the fire ruined the upper level of the 100-year-old dairy factory in Ruawai which had been converted to an apartment at one time.
Mr Bain said no one had lived in the apartment for about 10 years. The suspicious fire was being investigated by fire and police.
"At this stage there's no reason why we can see it as accidental because no one was there," he said.
Mr Bain said the fire was a reminder to owners of unused buildings to ensure they were secured.
"It's common sense. Remove the temptation, even if it's [to stop] the kiddies riding their bike in building. There's a level of responsibility regardless," he said.
Detective Andrew Bailey from the Dargaville police said he had received a number of leads but could not say any more.
As of yesterday the cause of the fire was still being investigated.
Anyone who heard or saw anything suspicious in the area around the time of the fire could call Dargaville police on 09 439 3400 or Crimestoppers on 0800 555 111 to remain anonymous.