An accused drug ring leader used Auckland's SkyCity casino as his office to plan P deals and enjoy a "high-roller" lifestyle, police say.

The man is accused of being the central figure in a drug bust codenamed Operation Ice Age, and is on trial at the High Court at Auckland with four others on methamphetamine charges.

Crown prosecutor Mina Wharepouri told the court that Tac Kin Voong spent most of his time at the SkyCity casino during the six months police had him under surveillance.

Voong used the casino as an office from which he would make calls on his cellphone to obtain methamphetamine, arrange meetings for drug deals and organise payment, said Mr Wharepouri.

He said that when arrested in his SkyCity hotel room, Voong had $11,000 bound in casino paper, a P pipe and a small amount of the drug.

In an interview with police, Voong had denied being a drug dealer, but explained his apparent success as a gambler at the casino.

He had said "he was so successful that he was able to employ other persons to play the slot machines on his behalf. And by using this approach he had won a number of jackpots," said Mr Wharepouri.

"Consequently, he enjoyed a lifestyle much like that of a high roller."

Mr Wharepouri told the court Voong would use others to move drugs and cash payments, including his "trusted lieutenant" Yihia Luo - also known as Joey Dai - and Ling Hui Yeh, Voong's girlfriend.

Yeh is also facing money laundering charges which accuse her of receiving money from the alleged drug deals.

She told police the money was from debts owed to Voong.

Two others are also charged. Chee Kent Tan was allegedly a customer of Luo, and Kuo Liang Tsai was allegedly a drug runner for Luo.

When police arrested Luo and Tsai, they found Luo had a key to a safety deposit box containing $20,000, and $57,000 stuffed underneath a spare tyre in the boot of Tsai's car.

Police working on Operation Ice Age between July and December 2006 intercepted more than 35,000 phone calls and text messages.

Each bugged phone was given a casino-themed code name, like Lucky Dice or Snake Eyes.

Mr Wharepouri told the court the group talked in code. One conversation between Luo and Man Kit Chow referred to buying two oranges, rather than grapes.

The Crown says "oranges" referred to ounces of methamphetamine, and "grapes" meant grams, the smaller measurement in which P is usually supplied.

Detective Sergeant Mike Beal told the court that an ounce (28.5g) of methamphetamine sold for between $12,000 and $17,000, and a gram sold for $600 to $1000.

The drug was then supplied to consumers in "point bags" - 0.1g - for between $80 and $120.

The police also tapped conversations between Voong and another Vietnamese man, Hung Trung Kha, in which money was discussed.

As the intercepted conversations have been translated into English from Cantonese, Mandarin and Vietnamese, defence lawyers have been cross-examining the police translators.

Mr Beal told the court that translations of bugged conversations in drug trials were often a "bone of contention".

The trial before Justice Patrick Keane and a jury is to resume today and is expected to last three weeks.

SkyCity's media relations manager, Connie Sprague, said yesterday the casino would not be making any comment.