A gang member was able to legally buy 18 high-powered firearms before police cottoned on - and now the cache has vanished.
The man, understood to be a patched member of the Headhunters Motorcycle Club, bought the guns, including high-powered semi-automatic rifles, with a value of about $30,000, between 2012 and 2015, the Herald has learned.
It is understood that in January, police went to the Northland man to revoke his licence and guns, only to find he had already sold them.
Police would not comment on the case except to say it was "very rare for a patched gang member to be issued a firearms licence".
Labour's police spokesman Stuart Nash said the case highlighted the changes needed to toughen current firearms laws to keep guns out of the hands of criminals.
"How did a person like this get a licence in the first place?" he asked.
"You've got to have a good character test ... and guys like this do not pass this in any way, shape or form."
A police spokesman said typically a gang member's convictions and/or associations would mean they fail the fit and proper person requirements.
"Being identified by police as a patched gang member or prospect is a specific process requiring evidence such as photographs, intelligence from operations, search warrants and other sources, and certain significant tattoos," he said.
"Not everyone who spends time with gang members is themselves a gang member or a prospect."
The alarming case comes as the Government looks to tighten laws on gun control to keep the weapons out of the hands of criminals following a number of high-profile shootings.
Pita Tekira, 29, was found dead at a Kokiri Cres, Porirua property on Saturday after an armed stand-off with police during which he shot and killed a police dog and an officer was hospitalised after jumping from a two-storey window.
Last month, Rhys Richard Ngawhiri Warren, 27, was arrested after allegedly shooting and injuring four police officers near Kawerau.
Also last month, police found 14 military grade assault weapons as they carried out a search warrant in Takanini.
The Law and Order Select Committee is reviewing a proposal for increased monitoring of firearms and the people who have access to them.
Proposals have included the need for increased monitoring of illegal firearms, which recommended changes similar to Australia's system.
In three states there, firearm prohibition orders are placed on known offenders applying heavy penalties for possessing firearms, knowingly being in the company of people with firearms, and knowingly residing at or visiting a location where there are firearms.
Police also have the power to conduct unwarranted searches on those people, or vehicles and houses they occupy to check if an order has been breached.
The number of gun licences refused has increased 12-fold in the last decade, figures supplied to the Herald under the Official Information Act this week revealed.
While the number of people applying for gun licences doubled from roughly 5000 in 2005 to 10,000 last year - the number of refusals rose from just 66 in 2005 to 795 last year.
However, police figures show a steady rise in the number of illegal firearms seized, with 1504 confiscated last year - a 50 per cent increase on four years ago.
Police Minister Judith Collins said the review was a priority and she was awaiting advice from officials before announcing the next steps.
"Firearms in the wrong hands is of serious concern. I am pleased that the Law and Order Committee has launched an inquiry into issues relating to the illegal possession of firearms in New Zealand."
Meanwhile, police said yesterday four brand new shotguns were stolen from a residential Ruawai property between Sunday and Monday.
Earlier in the weekend, three firearms and ammunition were stolen from a gun safe in a garage at a residential Ruatangata West property and two air rifles were stolen from a Mangawhai property.