A suspicious package containing cannabis and an unidentified white powder has been found at the NZ Customs Air Cargo Inspection Facility near Auckland Airport.
A fire service spokesperson said one hazardous materials truck is at the scene on Tom Pearce D, along with six fire trucks and police.
A facility staff member was exposed to the substance and is being assessed by ambulance staff.
Several firefighters have undergone decontamination after going inside the building.
Police say there is no indication the substance is harmful and it will be sent for further testing. It is currently in an airtight drum and has tested negative as anthrax.
A Customs spokesperson said no staff had been evacuated and referred further comment to police.