Customs has seized 35kg of cocaine in a ship docked at Port of Tauranga.
The illegal drug had a street value of about $15.7 million, consisting of about 350,000 doses, the agency said.
The ship arrived from Panama last Thursday. Customs group manager maritime Paul Campbell said the cocaine was found in the engine compartment of a refrigerated shipping container full of bananas that evening.
Two weeks ago, 140kg of cocaine was removed from a shipping container at the Port of Auckland.
"There is an economic cost with this criminal behaviour that includes disruption to legitimate activity on New Zealand's ports," Campbell said.
"While Customs risk assesses all incoming shipments and vessels, the time involved for physical searches is significant… clearance of other legitimate shipments becomes inevitably slower while we undertake inspections for suspect containers.
"This is time-consuming work but Customs, and port operators understand it has to happen to stop the criminal activity that threatens New Zealand's supply chain."
Port of Tauranga chief executive Leonard Sampson he understood the "value" of Customs' work, even if it delayed "legitimate cargo".
"Our security and operations teams are highly focused on safety and preventing any illegal activity at our port."