A squeeze on cigarettes is already causing fights in prison, says an ex-inmate just released from Waikato's Rangipo Prison.

The Government announced yesterday that cigarettes would be banned from New Zealand prisons starting next July, sparking warnings that prisoners could lash out at guards in protest.

"They've caused fights already. Even just for a cigarette paper guys are at each other," said the 41-year-old, released yesterday after a year in jail for his eleventh drink driving conviction.

Cigarette prices had gone up and wages down this year, he said, putting smokes out of reach for three-quarters of inmates.

"The Government better have a lot of patches," said the man, who asked not to be named.

"They [the inmates] scab. They go around and they might see cigarette butts on the ground and pick them up and smoke them."

Fumes billowed out of cells and prisoners without smokes attacked others, he said.

"They like their smokes. It helps them relax and it keeps them calm.

"There were no problems when everybody had smokes."

But the man, himself a smoker, said it was not a bad thing to have to quit smoking, and there were bigger problems in prisons than cigarettes.

They were understaffed, forcing guards to lock up inmates early at night, and many inmates were already angry at tougher penalties like the three-strikes legislation, he said.

"They just test you," he said.

Still, he was finding it harder being out of prison with nothing, he said.

"You get used to the bed, the food, the routine. And you get out here and it's hard. It's really hard."

He had cleaned and vacuumed in prison for $11 a week - down from $15 before this year's pay cut - and that made him one of the lucky ones, he said.

"I bought a coke and a sandwich today and it cost me $10.90. It's ridiculous.

"It's up to me now to get on my feet. I've done my crime, I've done my time."

Overseas, smoking bans in prisons have produced a few riots, black market smuggling, and some bizarre alternatives to tobacco by addicted inmates.

In Quebec, up to 70 inmates rioted and lit fires two days after a smoking ban came into force at the Orsainville detention centre near Quebec City in 2008. A total ban was rescinded the next day to allow smoking outside.

In Vermont, a thriving black market and prisoners smoking powdered juice led to an easing of its bans in 1992 to allow smoking outdoors.

The Edmonton Sun, meanwhile, reported that grass, leaves, tree bark, toast crumbs, pepper and nicotine patches had been smoked at a local prison, rolled in pages from the Bible and lit by sticking staples into electrical outlets.