Otago Coastal relieving area investigations manager Acting Detective Senior Sergeant Dylan Ross said officers executed a search warrant in Helensburgh.
A loaded sawn-off shotgun (over/under barrel configuration) was found hidden down the side of a child’s bed at the address, he said.
Two pistols were also found in a vehicle on the property.
Police also found cannabis, MDMA and drug paraphernalia.
A 31-year-old man living at the address has been charged with two counts of unlawful possession of a pistol, unlawful possession of a firearm, and possession of illegal substances.
Further charges were pending.
There were no links to gangs.
The raid followed several significant busts over the past two months in the South.
Police this week revealed they had seized eight firearms and a Taser during a series of raids throughout Levels 3 and 4.
Thirteen warrants were executed, and 13 people arrested.
