A new report into alcohol and drug use among police detainees shows a reduction in cannabis and alcohol consumption, while the demand for methamphetamine is on the rise.
The 2015 New Zealand Arrestee Drug Use Monitoring Programme Report reveals the proportion of detainees who felt dependent on methamphetamine increased from 20 per cent in 2011 to 35 per cent last year.
The number of people arrested who reported using the drug in the previous year also rose from 28 per cent in 2012 to almost 40 per cent in 2015.
These findings are consistent with record seizures of the drug made by New Zealand police and customs over the past two years, including 448 kg seized in Kaitaia in June.
Significant increases in the use of methamphetamine were noted in Wellington and Christchurch, with over 40 per cent of detainees in Wellington Central watch houses having used the drug in the past year.
The increased use in Christchurch is said to be caused by an influx of construction workers to the city, growing supply by gangs and post-quake stress.
The report also shows positive trends in reduced cannabis consumption among detainees in the previous year, from almost 80 per cent in 2011 to 69 per cent in 2015.
There has also been a reduction in alcohol dependency.
Those who had been drinking prior to their arrest also significantly decreased to 28 per cent, from 40 per cent in 2013.
Deputy Police Commissioner Michael Clement said the study was used as research in the Government's Tackling Methamphetamine Progress Report, released in October 2015.
"The proportion of detainees with convictions who had ever received treatment for drug and alcohol problems increased from 20 per cent in 2010 to 40 per cent in 2015," Clement said.
A significant number of detainees, however, felt they need help reducing drug and alcohol use according to the report. Twenty per cent felt they needed "a lot" of help to reduce substance use.
"Last month the Prime Minister announced that almost $15 million seized from criminals will be invested in anti-drug initiatives, with a greater focus on treatment," said Clement.
As part of the initiatives, police have received just over $6.2 million to be focused on disrupting the flow of illicit drugs from southern China to New Zealand.
Clement said this funding will also enable the expansion of asset recovery and financial investigations, recovery of legal costs, and a joint venture with the Northland DHB focusing on reducing demand for methamphetamine.
"Police believes that together with our partner agencies and our communities, we can successfully reduce the presence of this drug in New Zealand."
Other significant findings of the report include a sharp decline in use of synthetic cannabinoid following a ban in 2014 and an overall decline in the use of ecstasy.
The 2015 detainees were interviewed at Whangarei, Auckland Central, Wellington Central and Christchurch Central watch houses.