Roll-your-own tobacco is ''more dangerous'' than factory-made cigarettes and should be banned, says Professor Richard Edwards, head of public health at the University of Otago's Wellington campus.
Prof Edwards said roll-your-own tobacco was less natural and at least as harmful as factory-rolled tobacco and interventions were needed to encourage roll-your-own smokers to quit.
The interventions included mass media campaigns and pack warnings to correct misinterpretations that roll-your-own cigarettes were less hazardous and more natural.
A ''more radical move'' would be to ban the sale of loose tobacco, Prof Edwards said.
''Given that roll-your-own is more dangerous than factory-manufactured cigarettes, why do we allow them at all? Why not just get rid of them?''
In New Zealand, 38% of smokers rolled their own cigarettes, a rate much higher than anywhere else in the world, he said.
The Government should continue to tax loose tobacco more heavily than factory-rolled tobacco, he said.
''When the Government put up the tobacco tax quite substantially in 2010, they put it up more on roll-your-own than factory-manufactured and I'm suggesting that is something we might want to continue.''
The tax increase was justified because roll-your-own smokers rolled small cigarettes to make their habit cheaper than factory cigarettes.
In New Zealand, Australia, the United States, the United Kingdom and Canada between 21% and 40% of roll-your-own smokers believed their cigarettes were more natural and less dangerous than factory-made cigarettes.
However, evidence revealed roll-your-own cigarettes were at ''least as hazardous'' as any other type of cigarette and had a much greater concentration of additives than manufactured cigarettes, Prof Edwards said.
In New Zealand the ''concentration of additives is higher in loose tobacco at about 18%, compared with 0.5% for factory-made cigarettes'', he said.
Evidence also revealed there was a high rate of roll-your-own cigarette smokers in disadvantaged groups in many countries, there being higher usage among New Zealand Maori, black South Africans and smokers of lower socioeconomic status in Australia, the United Kingdom, the United States and Canada.
In New Zealand, roll-your-own smokers were more likely to have been diagnosed as having ''mental health, drug use and alcohol-related disorders and to have hazardous drinking patterns'', Prof Edwards said.