A gang of baby weasels has been discovered in a container of tyres recently arrived from Malaysia.
They were discovered at a transitional quarantine facility in Te Rapa, Hamilton, by a port worker last month.
Ministry for Primary Industries (MPI) north ports manager Sharon Tohovaka said although the weasels were dead, they could have been carrying pests or diseases harmful to New Zealand's primary industries or environment.
"The worker did the right thing by immediately closing the container after the find and then calling MPI to check the remainder of the consignment," she said.
"If they had arrived alive and managed to get free there would have been greater biosecurity risk - the possibility of a new weasel species causing havoc with our native wildlife."
Ms Tohovaka said the exact species of weasel was not identified, and described the interception as unusual.
Transitional facilities are locations MPI has approved to inspect, hold, or process biosecurity risk goods. Facilities that receive sea containers must have MPI-trained personnel available to check the containers for biosecurity risks.