Fire investigators have been unable to determine what caused a blaze that badly damaged an Auckland school's building.
At least 60 firefighters tackled the blaze in the technology block of Northcote College at its height on Friday night. The fire was spotted by a security guard shortly before 8pm.
The Fire Service today said the cause of the blaze was not believed to be suspicious. However, fire investigators had been unable to determine the cause.
Tests had shown no sign of an accelerant in the area where the fire started, and the building was secure when the fire was discovered.
The Fire Service said its investigation had now been closed.