A retired police officer who dealt with some of Christchurch's meanest criminals says all drugs should be decriminalised.
Former detective sergeant Al Lester said making drugs legal would take the power away from criminals who make huge amounts of money from the trade – and stop those committing offences to fund drug habits.
"Seizing drugs and prosecuting users is a system that is failing, so why not try another approach?" Lester said.
He calls for drug users to be treated as patients rather than criminals with drug use falling under the health system in his new book Straight from the Pig's Mouth.
Decriminalising drugs is different to legalising drugs, in that users would not be put through the justice system. Drug dealers would still face punitive measures.
"It's clear the system isn't working and if you keep doing what you've always done and expect a different result, well that's the definition of an idiot."
Lester said he did not think his views were "radical" but wanted to start the debate.
And his calls are backed by high profile criminal lawyer Nigel Hampton.
"I've been saying that for two or three decades . . . Decriminalise it and regulate it, you would take the black market out of it, take the gangs out of it," he said.
Hampton said the majority of the country's growing prison population was made up of people convicted on drug charges. Instead of prison, users should be treated with therapy, he said.
New Zealand's methamphetamine trade alone is estimated to be worth $1.2 billion per year.
But Canterbury University criminologist Greg Newbold, who spent more than five years in prison for selling heroin in the 1970s, did not agree.
"Decriminalising drugs is a big call, I could see a whole lot of problems with it. . .you would have to look at each drug on a case by case basis, you couldn't just make a blanket change."
Newbold said "all sorts" of other social problems would ignite, including "junkie tourism" and an increase in addicts.
"At the moment the punitive approach is the only way to go."
A police spokeswoman said the role of police is to enforce the law.
"Any questions relating to changes in legislation should be directed to the Government."
Police Minister Stuart Nash and Justice Minister Justice Andrew Little both say there needs to be a conversation had around drug reform, which could happen during the referendum on legalising medicinal cannabis.
Lawyer Nigel Hampton says the majority of the country's growing prison population is made up of people convicted on drug charges.
While social services also support Lester's call.
Director of the Salvation Army bridge alcohol and other drug addiction services Lieutenant-Colonel Lynette Hutson said it believes drug addiction should be treated as a health issue.
"Reflecting this in the law would hopefully mean more resources are directed to addressing addiction, including more treatment plans," she said.
Community Action on Youth and Drugs senior project worker Paul McMahon said the war on drugs was a "monumental failure" and New Zealand should take a health based approach.
"Instead of using the courts, people should be directed to get the help that they need," he said.
In 2001, Portugal became the first country in the world to decriminalise possession of all drugs.
