The reason a box of firearms "stumbled over" by a child was partly hidden on the Roxburgh Gorge cycle and walking trail remains a mystery to Alexandra police.
The boy, who was with his father, found a military ammunitions box containing the firearms in a rocky hollow on the trail in March, Constable Sam Williams said yesterday.
They were mid-way along the Alexandra-to-Roxburgh trail. The boy's father immediately contacted police.
"After exhausting all possible lines of inquiry, and coming up with nothing, we've decided to appeal to the public to see if anyone can shed any light on it," Mr Williams said.
"It was only by chance a member of the public found the box.
"It does seem unusual for the box to be stored in such a manner, as if for some form of safe-keeping and we can only speculate on the reason ... of course, any firearms licence holder knows that firearms have to be secured," he said.
There was no ammunition with the unloaded firearms and he declined to specify the type of firearms, or number, aside from saying there were "several".
Those details were part of the investigation into the matter.
The box was a military one, dating back to the 1950s or 1960s, probably used by the New Zealand Defence Force in the past. Such memorabilia was "readily available" for collectors to buy, Mr Williams said.
Anyone with information is asked to contact the Alexandra police or give information anonymously though the Crimestoppers number - 0800 555 111.