Police are urgently seeking a 38-year-old man after weapons - some handed in for destruction - were stolen from the Palmerston North police station.
At least one of the 11 guns stolen from the station yesterday morning was a banned weapon.
Acting Central District Commander Inspector Sarah Stewart said police were embarrassed about the theft, and it shouldn't have happened.
She said the police would do everything they can to ensure it doesn't happen again.
Ms Stewart said people should still have faith in the ability of police to keep recently banned firearms safely secured during the gun amnesty period.
Acting Central District Commander Inspector Sarah Stewart told Checkpoint one of the 11 guns stolen was "unlawful".
The exhibit storage area they were held in was secured, she said, but declined to provide further details.
She she had no information at this time that ammunition was taken.
Police are looking for Alan James Harris in relation to the burglary. He was known to police through previous dealings with him, she said.
Police and Armed Offenders Squad staff have searched Palmerston North properties over the past 24 hours as part of the ongoing investigation.
The burglary occurred early on Thursday morning. Police say a member of staff disturbed a person in the yard area of the police station around 7.40am. They say he left the scene in a vehicle, which police have since recovered along with another vehicle linked to the same person.
Police said Mr Harris is still believed to be in the Central District area, and police are urging anyone who knows his whereabouts, or is in contact with him, to contact them immediately.
Earlier today, Ms Stewart said the burglary was being taken very seriously.
"Locating Harris is a high priority for Central District Police. I urge anyone with information about his whereabouts to come forward to police. A warrant for his arrest has been issued. He should not be approached.
"Eleven firearms which were in an exhibit storage area are currently unaccounted for. I should be clear that these were not police firearms, but were a range of weapons being held as exhibits or handed in for destruction.
"I am very concerned about what has occurred - it is absolutely unacceptable," she said.
Commissioner Mike Bush has directed an investigation be conducted into how an offender was able to gain access to the police station, as well as an immediate audit on security around firearms at all stations nationwide.
Burglary follows ban
The burglary comes after Prime Minister Jacinda Ardern announced a ban on all military-style semi-automatic weapons and all assault rifles in the aftermath of the Christchurch mosque attacks. Prior to the announcement, many gun owners voluntarily handed in their weapons to police, though the police cannot say how many they received.
On social media, some gun owners posted about taking their guns to the police to be destroyed - and the prime minister encouraged anyone who has contemplated following suit to do so.
The Arms (Prohibited Firearms, Magazines and Parts) Amendment Bill passed its final reading in Parliament earlier this month. The law change had near uanimous support, with ACT the only party to oppose it.
During a media conference earlier this month, deputy commissioner Mike Clement said police didn't have the ability to safely store all guns expected to be handed in after the law change.
"Police already undertakes the surrender of firearms routinely across the country with regard to existing law, so we'll be replicating those processes, acknowledging clearly that the volume will be far greater," Mr Clement said.
Asked if police could store firearms safely, Mr Clement said it was something the police were working on.
"We're quickly developing processes to make sure we can meet that expectation," he said.
"That's why I urge gun owners to register online, be patient, keep the firearms secured, so that by the time that New Zealand police is ready to receive those firearms, we can do so safely."
'Police were confident they could manage the collection'
Police Minister Stuart Nash said he had sought fresh assurances that firearms storage facilities at police stations are secure and fit-for-purpose.
Mr Nash said at the time the government announced the amnesty and buyback on banned weapons, he sought assurances that strong systems and processes were in place to handle surrendered firearms.
"Police told me they were confident they could manage the collection of these firearms.
"I have now sought fresh assurances from the Commissioner that all stations and firearms-handling processes are secure and fit for purpose, and that firearms are stored safely, whether they are crime scene exhibits or otherwise.
"I have also asked for more detail about additional security measures police will have in place to ensure they can manage this process", he said.
Mr Nash is calling on the offender to hand himself in. "I also urge his associates and family not to shelter him or assist him, but instead urge him to surrender to police".