A Northland kaumatua who works with inmates at Ngawha prison says remand prisoners were responsible for a short riot on Sunday.
The prison at Kaikohe called for help from a riot squad from Auckland to put down an outbreak of vandalism after prisoners staged a protest there.
Mac Anania, whose hapu Ngati Rangi runs cultural programmes at the prison, says remand prisoners are often agitated because they are usually smokers who suddenly find themselves in prison - going 'cold turkey'.
He says they are offered gum or patches to ease the craving for nicotine but the non-smoking rule is the one they find hardest to handle.
Mr Ananis says it is now a year since Ngawha and other prisons went smoke-free. Long term inmates seem calmer and healthier since tobacco was banned.
The Corrections Department says the incident was brought under control within an hour.