The police fines office Wellington will be shut down for at least 24 hours while scientists examine white powder sent there today.
The Infringement Bureau was evacuated and one woman had to be decontaminated after the suspicious powder was discovered in an envelope just before 10am, police spokeswoman Elizabeth Young said.
Five fire engines - including a hazardous material unit - were sent to the office in Cuba St's Terralink House.
The ground floor of the building was sealed off and the woman staff member who opened the letter was put through a decontamination shower.
She was then sent to Wellington Hospital's emergency department, but was in a stable condition with no symptoms of poisoning, Ms Young said.
Police would not be looking for the sender of the envelope until they knew exactly what the substance was, she said.
"The ESR have it and from what I understand it could take 24 hours to screen it and get some results." The office would be closed down until those results were known, she said.
The bureau is responsible for issuing speed camera tickets and other driving related fines.
