Biosecurity staff have a new tool for keeping destructive pests and diseases out of the country - a mobile X-ray machine.
The machine will be stationed at Waitangi, Napier, Gisborne and Auckland, scanning the bags of some of the 260,000 cruise ship passengers expected to disembark during the summer.
Earlier this year, parts of inner Auckland were put under strict restrictions after the discovery of the Queensland fruit fly.
Ministry for Primary Industry spokesperson Brett Hickman said passengers took food from ships and brought it ashore without thinking of the consequences.
"We find that a lot of this fruit could harbour fruit fly and we know what happened last summer.
"Most of these ships do come from Australia, where fruit fly is rampant, and a lot of the Pacific Islands as well," he said.
Mr Hickman said in winter the X-ray machine would be used in fast freight warehouses.