A licensed gun dealer has been charged with selling firearms and ammunition to unlicensed customers.
During an investigation police searched an Auckland home and a firearms retail business.
The dealer appeared at Waitakere District Court last week, also facing charges relating to dishonesty and the unlawful possession of prohibited firearms and magazines, police said.
Firearms Safety Authority director of operations Superintendent Richard Wilson said selling guns to individuals who were not lawfully able to possess them would become a lot harder over time with the new Firearms Registry, which did not yet have dealer stock registered on it.
"This is why having a registry is so critical to keep firearms out of the hands of criminals and gangs.
"When fully rolled out, it will allow police to trace where criminals have obtained their firearms from."
Before the registry was in place a licence-holder could sell to another licence-holder, but was not required to produce a record of who they sold the firearms to - meaning the guns were untraceable, he said.
Diversion of firearms was a significant source of how gangs obtained firearms, he said.
"Over 70 percent of firearms seized by police are rifles and shotguns that can be obtained by standard licence-holders."
In December last year another firearms licence-holder was charged at Waitematā Court with the unlawful possession of over 35 firearms and ammunition in excess of 15,000 rounds for those firearms.