Police fear a haul of guns stolen in a daytime burglary near Greytown will fall into the hands of gangs and other criminals.
Eleven guns, a mixture of shotguns and rifles, were stolen from a locked gun cabinet at a Morison's Bush house sometime between 10 and 11am on Tuesday.
Head of the Masterton Tactical Crime Unit, Detective Sergeant Dean Cadwallader, said police were worried the guns could be used to commit more crimes.
"Our concern is that criminals or gang members will end up with these weapons and make it unsafe for the public and police, and be used in further offending and the like."
It appeared to be an opportunistic theft and anyone with information should come forward, he said.
"Somebody has got to know something."
Homeowner Kate Rothery said the guns were a mix of old family heirlooms and newer guns that her husband used for duck shooting.
"It's in the wrong hands and they are probably going to make them sawn-off shot guns, when they were beautiful, beautiful pieces of history."
The burglars had got into the house by wrenching open a window left ajar for an elderly cat, she said.
Disregarding laptops and the television, they stole just a Playstation before getting into the garage and making off with the whole gun cabinet, Mrs Rothery said.
"It's just such a shame and it's an invasion."
"It was a weirdly dumb break-in."
Her neighbours had noticed a white vehicle backing up to the garage, but had not realised anything was amiss, she said.
She believed there were probably two burglars.
The scary thing was that they must have known when the family was out of the house, she said.
Anyone with information should contact Masterton police on 06 370 0378 or call Crimestoppers anonymously on 0800 555 111.