Cannabis convictions in Northland have fallen by nearly two-thirds in the past six years - further fuelling calls for government action on drug law reform.

Ministry of Justice figures released under the Official Information Act to the Northern Advocate reveal the number of people convicted for cannabis possession in Northland courts fell from 227 in 2009 to just 83 last year - a drop of 63 per cent.

Drug Foundation executive director Ross Bell said the drop in convictions was because police had "almost de facto decriminalised cannabis" and were more likely to issue warnings for low-level drug offending, which do not appear on an individual's criminal record.

These figures follow a recent Drug Foundation poll, which found 64 per cent of Kiwis surveyed said a small amount of cannabis for personal use should be decriminalised or legalised, and 79 per cent were in favour of allowing medical use, such as pain relief.


"The public mood has changed. It's not a matter of if we will change the law, it's a matter of when and how we will change the law; what will it actually look like," Mr Bell said.

He said the use of warnings was positive but the Government was "irresponsible" for not making legislative changes to reflect how the law was largely being applied in practice.

"You can't just let police make up the law as they go along," Mr Bell said.

"What [John Key is] saying is actually [he's] comfortable with the police not enforcing the law.

"There is a point where politicians do need to be responsible and not accept that it's okay for the police to turn a blind eye."

Possession of cannabis can result in up to three months' imprisonment and/or a $500 fine.

Salvation Army Northland Bridge director Major Sue Hay said cannabis was not the harmless drug many young people believed.

She said users could develop a reliance and it could trigger previously unrecognised mental health conditions.

"It can absolutely exacerbate some of those more severe mental health issues. It's not as harmless as some believe. It can have quite drastic effects," Ms Hay said.

However, she said the current system of turning users into criminals was not working.

"Rather than going down the criminalisation route, I would love to see people referred to treatment. That's where I would be heading - moving away from justice to health."

A number of national bodies, including the Law Commission, the Treasury and the
Institute of Economic Research, have highlighted the pitfalls of prohibition and the benefits of cannabis reform.

The bodies suggested that decriminalisation or legalisation would reduce harm for users and result in hundreds of millions of dollars of economic benefits annually.

Mr Bell said the Drug Foundation poll, which was undertaken by Curia Market Research, showed support for reform across all major political parties.

"Politicians should now be able to proceed with cautious reform without fear of a voter backlash, but any new system needs to protect young people and those communities that already experience the harmful effects of drug use. Any new approach should be carefully designed to improve not worsen drug harm," he said.

Nationally, 17,218 cannabis-related charges were laid in 2009. This figure has dropped each year and was 6492 last year - a drop of 62 per cent.

Number of people convicted for cannabis possession in Northland courts:

* 2009: 227
* 2010: 208
* 2011: 165
* 2012: 91
* 2013: 74
* 2014: 90
* 2015: 83

- Source: Ministry of Justice