At present, about 17 per cent of adults smoke daily.
The institute's addiction research leader, Dr Natalie Walker, said the findings, to be presented to the Smokefree Oceania conference in Auckland tomorrow, were strong evidence that using low-nicotine cigarettes reduced levels of tobacco addiction and helped smokers to quit the habit.
"Therefore, we believe limiting the nicotine content of all cigarettes sold in New Zealand will help the Government achieve its goal of a smokefree New Zealand by 2025.
"We found that if cigarettes with a high nicotine content cost more than cigarettes with low nicotine content, smokers would mix the type of cigarettes they smoked to achieve a balance between nicotine craving and cost.
"However, this created a dual-use scenario where people still smoked regular strength cigarettes, alongside low-nicotine-content varieties."
She urged the Government to regulate to permit the sale of only very-low-nicotine cigarettes, rather than following a suggestion for a nicotine-based tobacco tax in which very-low-nicotine cigarettes were taxed at a lower rate than regular smokes.
For a two-tier system to work, she said, the price difference would have to be at least $10 to $15.
Health Ministry tobacco policy chiefs could not be contacted last night, but Dr Walker said she had discussed the trial with them yesterday and they were "looking at the results".