The Firearm Licensing Authority (FLA) says 299 guns have been reported lost or stolen over the last five years.
Chief Executive Officer of the Firearm Licensing Authority Shane Dalling said this poses a national security risk since these weapons presumably "go into the hands of criminals".
Mr. Dalling argued that an "overwhelming majority" of cases where firearms are reported lost or stolen are as a result of negligence and "could be prevented easily".
The most common cases, he said, are of people who claim their firearm had been left in their vehicle.
He said the police are taking a proactive approach in dealing with reports of firearms being lost or stolen, by bringing charges against the licence holders where applicable.
But he noted that even if the individuals are not charged by the police, the FLA will still revoke their firearm licence, unless it is "satisfied that the persons did all that they could possibly do to have prevented the loss of that firearm".
Mr. Dalling was speaking Monday morning on Power 106's Morning Agenda.
Member of Parliament Phillip Paulwell is the latest high profile figure to have been charged with negligence after reporting that his licensed firearm was stolen from his vehicle.