An angling group is urging the Conservation Minister to say no to a proposed grass and silver carp farm near Lake Taupo for fear they will escape and destroy the lake.
But the group behind the proposal says there's no danger.
One-hundred-thousand fish could soon be swimming in ponds, with 1 tonne a week to be shipped to Auckland restaurants.
But opponents like the Federation of Fresh Water Anglers and the Outdoors Party say the silver and grass carp are invasive.
"Countries all around the world now are spending a fortune, vast amounts of money, trying to exterminate the silver carp, and here we are trying to release them right next to the most beautiful lake in New Zealand, in fact in the South Pacific," says Alan Simmons, from the New Zealand Outdoor Party.
The site is 6km from Lake Taupo, 2.5km from the Waikato River, and its proponents say there'll be no discharge from the ponds.
But opponents say just as catfish ended up in Lake Taupo and multiplied, so will the carp.
"No matter what happens and wherever these fish have been released before there have been all the assurances in the world and they've still escaped, whether a human carries it or maybe a bird carries it. It will happen," says Mr Simmons.
But those behind the proposal say the lakes and rivers are too cold and the rivers aren't long and fast enough.
"It's a still body of water, so there's no water flow, so there's virtually no chance they'll be able to establish a population," says Richard Clark from Golden Harvest Aquaculture.
In the United States there is a huge problem with silver carp leaping from rivers.
Even though they grow up to 40kg, they're easier to shoot than hook because they only eat plankton.
Mr Clark says Conservation Minister Maggie Barry gave permission to transfer and release the carp yesterday with special conditions, but he's still waiting for a fish farm licence.