Police are investigating allegations of serious breaches in their vetting of the accused Christchurch killer for his firearms licence.
A former head of firearms control for the police, Joe Green, has alleged in an article on the website Kiwi Gun Blog, that police did not follow the required procedure to ensure only fit and proper persons are licensed to buy and use guns.
Mr Green said in the article that the offender applied for his firearms licence in a police district in which he might have an increased chance of getting it approved.
He said it appeared the officer did not interview a person who knew the offender best, usually their spouse, partner or next of kin.
"The process requires the interview of an unrelated referee," Mr Green said in the article.
"I understand that two people were interviewed. They knew the offender primarily through an on-line chat room. Both referees are recorded as saying the same."
He said the offender allegedly declined to be interviewed at his home and was instead interviewed at his place of work and there was doubt that a home visit and security inspection took place.
"This outlines a classic scenario for someone setting up to obtain a firearms licence for nefarious purposes, and because due process was not followed, he succeeded," Mr Green wrote.
"Changing the law in terms of the possession and use of firearms by law-abiding people will have little effect on safety unless the integrity of the licensing process is maintained."
Mr Green could not be contacted for comment.
The Police Commissioner, Mike Bush, was asked about the allegations at a press conference today. He responded that police were working through the "suggestions" but he would not comment until police had all the information.
In a statement, police said the investigation team was making a large number of enquiries and they were not in a position to go into specifics.