A top secret police investigation has pulled off the biggest cocaine bust in New Zealand history. Auckland police revealed the $14 million seizure yesterday.

The 35 1kg bricks of high-grade cocaine were flown into Auckland from Mexico in May, hidden inside a diamante-encrusted statue of a horse's head.

After weeks of intense surveillance and intelligence work, police swooped on Friday morning, arresting a 44-year-old Mexican and a 56-year-old American at Auckland International Airport. The pair were bound for Hawaii.

They appeared in Manukau District Court yesterday morning, charged with importing a Class A drug and possession for supply of a Class A drug. The Mexican has been granted interim name suppression until tomorrow when he will reappear. The American, who will also reappear tomorrow, is also seeking name suppression. They remain in custody.

Shortly after police revealed the bust, a 29-year-old Mexican was arrested in Christchurch and will face the same charges.

Police say more arrests are likely and refuse to rule out Kiwi involvement.

"This is a significant win for New Zealand," Detective Superintendent Virginia Le Bas said.

"This is a great success, we should be proud to have detected it at the earliest of stages."

The horse head, which weighs 365kg and stands just 1m tall, had been packaged to an Auckland address, but it's not clear whether New Zealand was intended to be the final destination.

Police will continue to work with Customs and international agencies to find out where the cocaine was meant to end up.

"There is a market for cocaine in this country and generally, the market is high society people or socialites," Le Bas said.

The record cocaine bust comes less than a month after New Zealand's biggest drug seizure, when $494m worth of methamphetamine was discovered after a boat was found abandoned on Ninety Mile Beach.

Customs group manager Jamie Bamford said the bust proves New Zealand cannot be used as a soft target.

One of New Zealand's top drug experts, Massey University chief researcher Dr Chris Wilkins, said it is possible the shipment was ultimately headed for Australia's east coast.

However, he also said years of research on drug use has revealed a rise in Kiwis admitting to using cocaine.

Importing the class A drug cocaine is punishable by life imprisonment.