"We want to hear from any firearms holders in the Northland and Auckland areas who might have had the same thing happen to them, but thought nothing of it," Detective Andrew Bailey of Dargaville police said.
"Establishing whether this has any link or not to the recent firearms theft in Dargaville is a priority for us, but as we continue our enquiry we are warning anyone with firearms to ensure they are stored securely.
"That includes reviewing where you leave your keys to the gun safe, if someone breaks into your home they will have a good look for those keys; don't make it easy for them."
Police also revealed today that no ammunition was stolen during the burglary on May 17.
They are appealing to ammunition retailers and manufacturers to be wary of people asking for ammunition for AK47 or AK74 weapons.
"The guns stolen were AK74s but the offenders may approach retailers or manufacturers looking for ammunition for AK47s as they are similar, just a later model," Mr Bailey said.
"We need to hear about any of these approaches. Again, we remind people that these guns are in the hands of criminals and we cannot deny the risk they continue to pose to the community whilst that is the case."
Anyone with information is asked to contact Mr Bailey on 021 1915 765 or Crimestoppers, anonymously, on 0800 555 111.