The tobacco tax is hurting those who are most vulnerable and smoking rates among some communities remain stagnant, despite the tax.

The government's reviewing the consequences of its annual increase in tobacco tax, such as increases in crime and the financial impact on smokers.

Massey University public health professor Marewa Glover told Kate Hawkesby the tax is taking money out of the hands of families who are already financially stressed.

"It's the people in the lower socio-economic groups where smoking is highest and people with other mental health difficulties. They are not able to stop that easily.

"It is an addictive behaviour to smoke, it's not as simple as saying, 'well, it will get to the point where they'll just stop', no they're not."

LISTEN ABOVE AS MAREWA GLOVER SPEAKS TO KATE HAWKESBY