Fire investigators are yet to establish what caused a massive fire in a used car parts warehouse in south Auckland last night.
The blaze in Select Auto Parts warehouse in Penrose began about 9pm and took 60 firefighters over an hour to bring under control.
Firefighters attacked the blaze from the ground and from above with two aerial ladders getting over the roof to pour water onto the burning building.
One fire appliance remained on duty overnight to guard against a flare up and the building was cordoned off by police.
Fire investigator Russell Dixon said the building was completely destroyed by the blaze and would have to be bulldozed.
The fire was being treated as suspicious at this stage, he said.
"We've got to and check everything so that includes the fire being deliberate and, like the police do, we deem an incident suspicious until proven otherwise."
The building was locked and no one was supposed to be inside when the fire started.
Fire investigators were continuing their detailed scene examination.