An Auckland firearms owner whose details were stolen from a disused police station wants answers from cops over how much risk he and is family are in.

He said he is prepared to take what he described as the "nuclear option" and dispose of his firearms if his family is in real danger.

Earlier this month, the Herald revealed that confidential files of firearms owners were among a trove of documents allegedly stolen from the old Auckland City police station in Vincent St.

Police have launched a major investigation into the privacy bungle, which they are describing as extremely disappointing.

Several people are before the courts after the documents, along with expired police pepper spray, were recovered after officers executed a search warrant in Mt Albert in May.

Police initially said people who had their firearms licences processed at the Vincent St station between 2015 and 2017 were affected.

Yesterday, in a public notice, police announced anyone who dealt with the Auckland City District Arms Office from 2003 to 2018 was potentially caught up in the breach.

"Police are extremely disappointed that this has happened," the notice yesterday said.

Auckland City District Commander Superintendent Karyn Malthus said police continued to analyse more than 4000 stolen documents they later recovered.

Malthus said police believed the incident involved an "opportunistic burglar", with no known gang links, who was allegedly targeting copper piping.

Police had not established any link to organised crime from the Vincent St incident, she said.

One of the firearms owners caught up in the breach has spoken out, on condition of anonymity.

He is among the owners whose names and addresses were on the stolen documents.

But he had also provided an arms officer details of the number, type and calibre of firearm he owned, and believed this was also held on file.

He wants clarity from police on who may have had access to the information, the level of threat they posed and how widely his details may have been shared.

"I need to assess the risk that this situation has put me in, so that I can take appropriate steps, up to and including a nuclear option, where we just get rid of it all," he said.

If his guns are at serious risk he said he would like police to offer another buy-back scheme rather than force him to ditch his lawfully obtained firearms.

He would also want a letter from the police commissioner stating his firearms had been disposed of.

"I've been doing this for many, many years, there's a considerable sum of money tied up in these things, and no, I don't want to give them up. But, you know, I need to make a risk assessment."

He said officers who had phoned him had offered minimal information that would allow him to assess the risk the breach had placed him and his family in.

They had cited the fact people were before the courts as why they couldn't tell him too much, he said.

The officers' advice was to store his firearms safely.

But this advice was no use if someone was at his door asking where his guns were, because they could just force him by threat of violence to him or his family to unlock his secure storage.

"Because if I get a knock at the door ... I'm handing the keys over, right?

"You can put it in any box you want and you can use as many locks and the concrete can be as thick as it needs to be.

"But if it's openable by me, I will be opening it."

He also said police seemed focused on the privacy breach, instead of the risk to the safety of firearms owners via burglaries.

"I'm pretty annoyed about my privacy. But why aren't we talking about the real issue here?

"I need enough information to assess the risk to me and my family."

Of the documents recovered, 444 contained the names and addresses of firearms licence holders, whom police were working through contacting, Malthus said.

Another 1500 documents recorded only address details of firearms owners.

There had been two firearms-related burglaries in Auckland Central since the Vincent St burglary, she said.

"Offenders were apprehended in both instances and there has not been any link identified between those incidents and the Vincent St burglary.

"While police acknowledge the news of this breach would be distressing for those affected, we are reassuring licence holders that Police have recovered their documentation and we are evaluating those items to identify all persons affected."

Police have established a dedicated 0800 line for firearms owners who wish to discuss the incident, 0800 462 379, along with the email address [email protected]