A split has emerged between New Zealand and Australia over the approval of a type of genetically-engineered (GE) corn.

The New Zealand Food Safety Minister has overridden the joint food authority's approval of the corn for human consumption.

New Zealand has deferred the approval of Monsanto's high lysine genetically-engineered corn under its Food Safety guidelines.

The corn is engineered to add weight to pigs and poultry but has been approved for human consumption by Food Standards Australia New Zealand (FSANZ).

FSANZ's Lydia Buchtmann says the GE corn is safe for humans.

"We've gone out and done additional work on this, and had it peer reviewed so we're highly confident that it's safe," she said.

Greenpeace's Louise Sales says only uncooked GE corn has been tested on animals.

"It's the cooking process that can actually cause the formation of dangerous compounds," she said.

The joint food authority says the approval is in case the GE corn is accidentally mixed with food products