Liquid cocaine worth $1m found in tequila

These tequila bottles hid liquid cocaine estimated to weigh 1kg. Photo / Supplied

The American tourist accused of smuggling $1 million of cocaine in bottles of tequila had been to New Zealand three times in six months - triggering concerns among authorities about what he was really doing here.

Peter Rhee, 29, arrived in Auckland on a flight from Los Angeles on February 6 but had little money and no real plan of what he wanted to do in the country.

"He didn't really have a plan of why he wanted to be here and that's the first thing that alerted the officer at passport control. He was travelling alone and he was a student," Customs drug investigations manager Mark Day said.

Rhee's earlier visits were of concern to authorities. "He's been here three times in six months so we're certainly concerned about what those trips were for. I don't think you have to be a rocket scientist to think they're the same deal."

After Rhee raised staff suspicions, he was taken to a search area where he became agitated and non co-operative.

"Things started to concern us. A student travelling from the United States is coming here - for what reason? When we looked through the luggage we found what was supposedly two bottles of tequila."

The seal of one of the bottles caught the attention of an official so the contents were tested and it came back positive for cocaine, said Mr Day.

The method of hiding cocaine in fluid is rare. "We've seen a couple of instances like this over the years, we don't get it a lot, it is relatively hard to detect when you have 140,000 people through Auckland Airport each week ... that are all carrying duty free."

Often it came down to staff using their instincts and experience when speaking to travellers. "If scenarios don't add up and when you're dealing with people day in, day out, you get a cycle go through your head so you see what a genuine traveller looks like."

Mr Day said the amount of cocaine seized suggested to him that the smuggler must have networks already in place.

Staff "conservatively" estimated the haul at between 750 grams and a kilogram with a street value up to $1 million.

There had been big seizures of cocaine in Australia recently and New Zealanders had become more involved in trafficking overseas, leading to heightened awareness of it at border control, said Mr Day.

The maximum penalty for importing cocaine is life imprisonment. Rhee will reappear in court this month.