One in ten firearms licence holders have a criminal conviction, including 10,000 for violent and sexual offending, Stuff can reveal. 

The figures reinforce the need for stricter gun control, New Zealand Police Association president (NZPA) Chris Cahill said.

But gun lobbyists say the offenders have paid their price, and have to be pass rigorous individual assessments just like every other gun owner. 

Of the 244,989 people who held a licence on September 16, over 30,000 of them have non-traffic convictions, figures released under the Official Information Act show. 

According to The Homicide Report, which analyses more than 1000 violent deaths in New Zealand since 2004, only a small minority of those who kill with a gun hold a licence. 

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In about 12 per cent of cases, the killer was confirmed to have been a licensed gun owner. In 70 per cent they were determined not to have held a licence.

NZPA president Cahill said the figures were "surprising" and underlined the need for changes to the current gun laws. 

"The convictions I would be concerned about are the 9000 violence and 1000 sexual ones," he said.

"It just shows that we are overdue to look at how the arms act operates. You see those figures and think they should be screened."

The new gun control bill, which is currently being debated at select committee, would stop many people with family harm or violence convictions from obtaining a firearms licence.

​Under the proposed bill, the ten year licence would be cut to five years and people would be disqualified from holding a licence if they have received serious violence, drugs or firearms convictions in the last ten years or have a protection order against them.

The cancellation of licences will not apply retroactively, according to a cabinet paper on the proposed bill.

Cahill said he supported the changes.

"The current test of a fit and proper person is not defined in law which makes it very hard to turn down a licence holder in the vetting process."

"That is why we are supportive of the changes going through now. They much better define the fit and proper person test. It clearly outlines what offences will prevent someone from getting a license."

The police figures also reveal that of the 51,678 people issued with a firearms licence from January 2013 to September this year, 4599 of them had a non-traffic conviction before the licence was issued. That is about nine per cent of people issued with a licence in that period.

There are another 27,000 offences for drugs and anti-social behaviour offences. 

Nicole McKee, secretary of the Council of Licenced Firearms Owners, said every applicant had to be assessed as being fit and proper to hold a licence based on their individual assessment, and not on tick-box questionnaires.

"Those that have committed offences and paid the penalty, some as far back as the end of World War II, shouldn't be used to understand the state of things today. Society has changed a lot over that time. The onus must be on making sure that the law we have now, which has proven to be effective, is enforced fairly, diligently and properly."

Gun Control NZ founding member Hera Cook said the number of firearms licence holders with violence convictions raised concerns.

"We want police to treat family violence and animal cruelty extremely seriously, but we don't want police to have a blanket approach to convictions."

"​I would want the police to pay a lot of attention if they are considering a firearms licence for someone with a violent conviction. I would be concerned about that."

"Family violence and animal cruelty convictions should be considered very seriously".

National's police spokesman Brett Hudson said said he still had faith in the police screening process for firearms licences.

"On the face of it, it seems a large proportion," he said.

"It is difficult to draw an absolute view without more information. What is clear is that some of those people have been convicted multiple times."

Acting superintendent Mike McIlraith said prospective gun licence holders were vetted carefully before being granted a licence.

He said everyone who applies for a firearms licence is interviewed, referees interviewed and vetted by police, and the person's 'fit and proper' status is decided based on a selection of criteria.

Details  such as the seriousness of offending, how historic it is, and whether people are able to demonstrate that they have changed their behaviour and are a 'fit and proper' person to hold a firearms licence.

"People who have criminal convictions are not treated any differently in this assessment than those that do not – each individual applicant is assessed on their own merits."