The head of the police union is calling for more frequent checks on licence holders and for all firearms to be registered to combat the rising trend of firearm theft in New Zealand.

Photo: Supplied / NZ Police

The number of firearms stolen in New Zealand between 2013 and 2017, 3298, has risen 35 percent compared to the five years before.

This year alone, 194 firearms have been reported stolen.

Information newly released under the Official Information Act shows police only employ the equivalent of just 259 full-time staff to monitor the country's more than 240,000 licensees.

That means if the monitors were all working full time they would each have responsibility for about 900 licence holders, but Police Association president Chris Cahill said the number of staff was more than enough.

Photo: supplied

"Well, when we talk to those firearms vetters, they don't think that the workload is excessive, bearing in mind that they only get to check either new applicants or people that are asking for a renewal so, once every 10 years," he said.

Mr Cahill said most licence-holders complied with the law, but some did not, and too many firearms were being stolen.

The Arms Act only allows police to check firearms security when they go up for renewal - every 10 years for standard licences - or when the licence holder moves to a new residence.

While those with pistol, military-style semi-automatic and restricted endorsements are subject to more stringent and regular inspection, most are not and Mr Cahill said that was a big concern.

"And the other issue we have is that because there's no registry of firearms ... or no need to have a permit to procure for category A firearms - which are the majority of firearms - someone could buy a large number of firearms within that 10-year period and there's no ability to check whether the security for those people is appropriate."

Police refused to be interviewed on air, but did provide statistics and a statement from acting Superintendent Mike McIlraith, of the Arms Act service delivery group.

However, Mr McIlraith did not address whether police resourcing of firearms vetters was appropriate to aid in limiting thefts, simply saying that theft was always a concern for police.

Mr Cahill said all firearms should be registered, like pistols and military-style semi-automatics already are, so they could be tracked if they were stolen or illegally sold.

However, Firearms Safety Specialists director Nicole McKee said there was no evidence a registry worked, and that existing registries of endorsed firearms were lacking.

"A lot of the firearms that are found by police in possession of criminals have registration numbers ground off them

"So we don't see how registering a firearm is going to benefit the community at the cost that will apply to that registration.

Ms McKee said New Zealand's current firearms regime was fit for purpose and appropriately resourced.

Firearms security was already being reviewed by police working with the firearms community to ensure consistency throughout the country, she said, with the results of that review expected to be released soon.

University of Waikato Professor Alexander Gillespie said that without research resourcing, assessing the impact of the Arms Act on firearm security and the illegal trade is impossible.

"Our difficulty is that we just have a large gap of knowledge and we just don't know how many firearms are in the country whereas a lot of other countries have got more resources to look at these questions.

"We don't have answers to them yet, and a lot of our answers have to come from comparisons to offshore."