Customs said one aim of the exercise was to show potential terrorists or WMD smugglers New Zealand was not a soft touch, and had advanced technology capable of intercepting weapons, explosives, and components.
The smuggling of nuclear weapons components was also discussed during Maru.
The Defence Force, Ministry of Foreign Affairs and Trade, Fire Service and Maritime New Zealand joined Customs during Maru. The agencies demonstrated detection and decontamination equipment, including a bomb-detection robot.
The specialist Explosive Ordnance Disposal (EOD) Squadron from New Zealand Defence Force used the British-made robot.
Officials told NZME News Service it was important to stay ahead of terrorists and criminal networks plotting to smuggle WMD components across busy borders.
"The world is a changing place," said Jamie Bamford, Customs general manger of intelligence, investigations, and enforcement. "We have a huge amount of people and goods passing through the borders every day."
Maru was about sharing lessons with New Zealand's friends and allies, Mr Bamford said, and the operation aimed to make the Asia-Pacific region safer.
This week's exercise was the first of its kind in New Zealand for seven years.
Senior Customs Officer Dave Hart of Tauranga demonstrated the HCV mobile truck, a $4 million container inspection unit.
The mobile truck x-rayed containers and vehicles and could detect suspicious objects hidden deep within seemingly innocuous cargo, Mr Hart said.
The HCV helped Customs look for "anomalies or inconsistencies" in cargo, Mr Hart said.
But he said the unit also had a useful role in stopping "revenue leakage" or unauthorised imports.
Some dodgy importers tried smuggling extra goods in containers to avoid paying tariffs, Mr Hart said.
His team was also familiar with some bizarre imports and live stowaways, such as animals including poisonous brown widow and black widow spiders, he said.
The animals were usually dead by the time they arrived in New Zealand.
Operation Maru started on Tuesday and concluded yesterday.
Customs described it as a "tabletop" exercise involving a shipment of dual-use chemicals arriving in a fictitious country.
The participants worked to apply their own laws to threats presented during scenarios.
Ms Wagner said it was the second Proliferation Security Initiative exercise under the Asia Pacific Exercise Rotation.
The rotation programme started last year with Exercise Fortune Guard, hosted in Hawaii.
MARU PARTICIPANTS:
Australia
Canada
Fiji
Indonesia
Italy
Japan
Malaysia
Mongolia
New Zealand
Papua New Guinea
Philippines
Singapore
Solomon Islands
South Korea
Sri Lanka
Thailand
Tonga
United States
Vanuatu
Vietnam
Western Samoa
World Customs Organisation
