A 59-year-old dental hygienist originally from Chile who was recruited by her son to serve in what authorities said was one of New Zealand's largest illegal drug syndicates has been ordered to serve 11 years and six months in prison.

Due to the seriousness of Mirtha Susan Ramos Mazuela's crimes, Justice Grant Powell also ordered her to serve at least 40 per cent of her term, instead of the typical 30 per cent, before she is eligible to apply for parole.

Ramos Mazuela was arrested along with her son, Hugo Patricio Alarcon Ramos, last year following a months-long police investigation called Operation Mystic. The international syndicate is accused of importing over a tonne of drugs, with Ramos Mazuela's son described as the top lieutenant on the ground in New Zealand.

But despite the large numbers — including $800,000 found in her apartment, 41 kilograms of meth and over 100,000 MDMA pills — Ramos Mazuela wasn't living large by a long shot, defence counsel Quentin Duff said at the hearing.

The only financial compensation she received for storing the drugs and money was $150 per week for rent and petrol, he said.

"The payoff appeared to be merely proximity to her son," he told the judge.

Ramos Mazuela earlier pleaded guilty to 12 charges involving importing, selling and possessing methamphetamine, cocaine, ephedrine and MDMA, as well as one additional charge of possessing materials for the manufacture of methamphetamine. All sentences will be served concurrently.

More than $1m cash was seized in the police investigation Operation Mystic. Photo / Supplied

Duff said his client was manipulated and bullied by her son into serving as a "storeman" for the syndicate — holding drugs at her apartment and repackaging them for sale. Alarcon Ramos was sentenced in September to 12 years in prison.

The alleged kingpin of the operation has name suppression as he awaits trial.

"It was her vulnerability and her ignorance that come into play," Duff said.

"Her son was directing her actions," he added, describing his client as "almost an abused participant".

But it was an argument the judge found hard to swallow. Given her education and the "extraordinary" quantities of drugs and cash, she should have known better, Justice Powell said.

"I accept that at the beginning she's brought in by her son. I accept that there's naivety and vulnerability," the judge said.

But the nature of her activities must have been clear in a "relatively short period of time", and yet she went on to be promoted from messenger to storeman, he pointed out.

"Education doesn't protect you from the ravages of abuse," Duff responded, pointing to the patriarchal society his client came from. She's lived in New Zealand since 2004.

Crown prosecutor Ben Kirkpatrick suggested the amount of drugs merited a sentence on the upper end of the scale. But he also acknowledged Ramos Mazuela appeared to be an "upstanding member of the community" prior to her offending.