A possible P-lab was engulfed in fire in West Auckland last night.
The Fire Service was called to the Te Atatu house at 11pm.
"There was possibly some drug manufacturing going on in the house," said a spokesman.
About 20 firefighters put out the blaze. They had to go through a decontamination shower to clean themselves of any potential hazardous substances.
No one was believed to be in the house.
A fire investigator was at the scene last night and is expected to come back this morning.