The fire department is on-site at Parliament after the delivery of a suspicious parcel.
A spokesman for Ardern confirmed it's not an explosive but precautions are being taken nonetheless. Several fire engines and the hazmat unit are at the scene.
A police spokeswoman said they were notified just after 10am about reports of "an item of interest" located at Parliament.
"Inquiries are underway to determine what the item is and assess any risk."
One area of Parliament has been isolated as a precaution, she said.
A spokesman for the Prime Minister said the item was sent in the post and received on level eight of the Beehive, the floor below Jacinda Ardern's office, and where her mail gets sent.
Newshub reports the item was an envelope containing white powder.