Seven stolen guns have ended up in the hands of criminals, Te Anau police say.
Sergeant Tod Hollebon said that between midnight and 5am on Sunday a ute parked at a property on Melland Place was broken into.
A shotgun and high-powered rifle were taken from the vehicle, as well as other items.
And earlier in the weekend, between 4.30pm on Saturday and 6pm on Sunday, a home on Dale Rd was broken into. Items stolen included five firearms taken from a locked firearms safe, Hollebon said.
"We are extremely concerned about these firearms getting into the hands of criminals and are investigating both burglaries thoroughly."
Police had carried out forensic examinations on the ute and at the Dale Rd property.
Hollebon said the burglaries were an important reminder that all firearms owners should regularly check the security of their properties and vehicles and ensure firearms were securely stored and not kept in vehicles.
If you have any information which could assist or may have seen anything suspicious in these areas over the weekend, please ring Te Anau police on 03 249 7600.
You can also give information anonymously by ringing Crimestoppers on 0800 555 111.