Police believe a significant organised crime group is behind New Zealand's largest cocaine bust.

They have made three arrests and say more are likely, after the cocaine - with an estimated street value of $14 million - was found inside a diamante-encrusted ornamental horse head airfreighted from Mexico.

Photo: Supplied

Two men, a 44-year-old Mexican and a 56-year-old American, were arrested at Auckland International Airport last night, trying to fly to Hawaii.

Another 29-year-old Mexican man was arrested in Christchurch this morning.

They have been charged with importing and possessing a class-A drug.

Photo: SUPPLIED

A joint investigation by police, Customs New Zealand and international law enforcement agencies led to the discovery of the drugs inside the 400kg diamante-encrusted sculpture in May.

Inside a cavity at the base of the head, they found 35kg of cocaine divided into 35 bricks.

Detective Superintendent Virginia Le Bas said the importation was part of a complex operation and a significant organised crime group was responsible.

Police did not yet know how long the men had been in the country, she said.

New Zealand Customs group manger Jamie Bamford said it did not tend to seize large amounts of cocaine, and last year discovered 1.5kg in small consignments.

Prior to this seizure, police said the average amount of cocaine they found each year was 250g.

Search warrants were being carried out at an address in Te Atatu in west Auckland this morning, and two houses in Christchurch are also being searched.

Two men and a woman were speaking with police.

Ms Le Bas said, based on police surveys, cocaine was not a common drug in New Zealand, but there was a market which was recognised as being associated with high society people, or, as she described it, "socialites".