Federated Farmers says the Ministry for Primary Industries (MPI) has done well to block a ship carrying potentially contaminated stock from anchoring on Kiwi shores.
But Labour biosecurity spokesman Damien O'Connor has called for the ship to be sent back to Malaysia.
Cargo ship MV Molat came from an unregistered facility and is carrying tonnes of palm kernel extract, which is regularly used as animal feed on farms. It's been anchored off the coast of Tauranga for a month, unable to offload its goods.
Federated Farmers' biosecurity spokesman Guy Wigley says MPI has done everything right.
"I think MPI need to be congratulated on taking a tough stance on the shipment and making sure that people don't cut corners with their responsibilities around biosecurity."
MPI is currently in negotiations with the ship's supplier.
Mr Wigley says there's no confirmation yet the extract is contaminated, but MPI's over-cautious approach is the right one.
"My understanding is there isn't necessarily any contamination in this line of palm kernel extract, it's just that it's not from an accredited source," he told Newshub.
"Whether it be a large bulk shipment of grain or palm kernel, or small packets of seed, they are very concerned to keep our biosecurity up to speed."
Labour says the shipment poses a "huge" risk and can't be allowed to reach our shores.
"Unregistered suppliers do not have to meet the stringent safety checks that registered suppliers do, to ensure there is no biosecurity risk to New Zealand. In this case, we do not know what checks were applied."
He says previous foot-and-mouth outbreaks have come as a result of contaminated palm kernel extract.