Correctional Service Commissioner Michael Waipo says the armory was accessed with the use of a key.
No suspects have been identified at this time however police are investigating the matter.
Waipo believes this is an inside job as a result of a tussle of the current position he holds.
The armory was last accessed on Monday.
“Instructions have been issued for the changes of both the deadlock and secondary lock. Arms in the wrong hands is dangerous for everyone,” he says.