The Ministry for Primary Industries is clamping down on the unlawful export of infant formula.
The ministry says a joint investigation with Customs has revealed substantial growth in illegal exports of formula primarily to China in the past year, with a total value of $150 million.
Manager of food and beverage Glen Neal says companies and individuals are being warned that to export animal product they must be a registered exporter.
He says it is also unlawful to export infant formula made for the New Zealand market to China, as that country has different product labelling rules.
Mr Neal says there are fines of up to $300,000 for acting as an unregistered exporter and the clampdown is an effort to protect New Zealand's reputation as an exporter of safe food.
As well, the unlawful exporting has led to a shortage of infant formula for New Zealand customers.
A milk products exporter says the Government's clampdown on unlawful exports of infant formula will preserve the reputation of the nation's dairy industry.
Westland Milk Products chief executive Rod Quin says in China infant formula can sell for two or three times its New Zealand wholesale price.