Emergency services have left Wellington's spy headquarters after an unknown white powder was discovered in a letter.
"The New Zealand Intelligence Community can confirm it is responding to an incident within Pipitea House caused by a letter containing an unknown white powder," a statement from the New Zealand Intelligence Community said on Monday afternoon.
"The Intelligence and security agencies take incidents like this seriously to ensure the safety of our staff."
A police media spokeswoman said the substance in the letter had been isolated and would be subject to further testing.
"There is not thought to be any further risk. Police are making further inquiries."
An area of the building was cordoned off as a precaution while emergency services and partner agencies attended the scene.
The "suspicious substance" was found soon after 3pm.
The building is home to the Government Communications Security Bureau (GCSB) and the New Zealand Security Intelligence Service (SIS).
The scare came almost-to-the-moment Prime Minister Jacinda Ardern announced a Royal Commission of Inquiry into the country's security agencies after the Christchurch terror attacks.
A Wellington Free Ambulance spokeswoman said no one in the building was treated by paramedics, or taken to hospital.
Everyone who was in close proximity with the white powder found in the letter was medically assessed, she said.