A vessel carrying 23,000 tonnes of palm kernel expeller (PKE) will not be permitted to discharge its cargo in New Zealand.
The Ministry for Primary Industries initially prevented discharge from the MV Molat after finding some of its cargo had come from an unregistered PKE facility in Malaysia.
The vessel arrived at Tauranga on 6 September.
MPI's decision comes after considering an application from the importer to have the PKE treated in New Zealand.
"We spent a lot of time assessing whether there was a solution that would meet biosecurity requirements, but unfortunately nothing ticks all the boxes in terms of mitigating the risk of pests and diseases entering New Zealand," says Steve Gilbert, MPI Border Clearance Services Director.
In making the decision, MPI considered the amount of product involved, the availability of heat treatment facilities in the region, transport and storage.
"My decision ensures that potentially contaminated PKE will not enter New Zealand," says Mr Gilbert.
MPI has strict biosecurity requirements for importing PKE. They include heat processing to at least 85 degrees Celsius, and that foreign facilities be approved and regularly audited by the exporting country.
"MPI has a lead role in protecting New Zealand from biosecurity risk. It's a job we take very seriously."