Raging fire leaves few clues

Fire investigators say extensive damage to an Auckland factory is making it difficult to determine the cause of the weekend blaze.

The Davis Trading factory in Carbine Rd, Mt Wellington, was left gutted by a fire which drew on most of Auckland's firefighting resources and an appliance from Hamilton.

Auckland deputy chief fire officer Graham Fuller said 20 trucks and 80 firefighters were involved in battling the blaze from 11pm on Saturday.

Mr Fuller expected crews would still be working at the site today.

"It went to a fifth-alarm fire, which is the greatest alarm we can have and effectively takes most of the appliances out of Auckland. We had an aerial appliance respond from Hamilton, as well."

The factory was still burning yesterday afternoon as firefighters started demolishing the building.

Mr Fuller said the fire was not being treated as suspicious.

"Because of the extensive damage it's going to be very difficult to ascertain what did cause it. The whole place is just absolutely destroyed."

He said stormwater drains were being pumped out to recover oil which ran from the bulk-foods factory.

The oil made the area slippery for firefighters and was a potential hazard to the environment, said Mr Fuller.

The Fire Service was working with the Auckland Regional Council to stop the oil getting into waterways.

Firefighters were pumping stormwater drains, said Mr Fuller, but there would be some contamination.