Six cannabis plants, almost ready for harvest, were found by members of Otago Lakes-Central CIB yesterday as part of their ongoing cannabis recovery operations.
The long grass around the crop contained wooden planks spiked with 10cm nails, Detective Senior Sergeant Malcolm Inglis said.
``They were big four-inch nails - if you stood on one if would have been pretty nasty,'' he said.
``This is a popular area where children often play and people regularly walk their dogs. It's really disappointing to see these people put at risk.
``Police are extremely concerned by this offending and would like to find the people responsible.''
The plants, which he estimated had a street value of about $5000, were found in the area near the gravel pit at the entrance to Glenorchy.
It appeared a similar number of plants had already been harvested from the crop and there had clearly been some recent activity at the site, he said.
``It's not massive amounts. The concerning fact is that someone has gone to the trouble of putting traps around it.''
The crop would have been planted in October and November, and police wanted any information from the public which might lead to the capture of the offender behind it.
``We have seen a lot of cannabis plantations before, but very, very few have man-traps,'' Det Snr Sgt Inglis said.
``It's certainly not common down these ways in the South Island.
``If we find out who was doing it there will be further charges in regards to laying man-traps.''
No officers were injured recovering the plants.
``A number of inquiries are being made to locate the offenders behind this,'' he said.
Police also dismantled a ``sophisticated'' cannabis growing operation in Glenavy yesterday.
Sergeant Kevin Reynolds, of Waimate, said five officers visited a property following a tip-off from the public.
A ``significant number'' of plants and amount of dried cannabis were discovered in an out-building at the property, but he declined to specify the amount or its dollar value.
``There was a number of plants ready to be cropped.''
No arrests were made, but Sgt Reynolds said police were following several positive lines of inquiry.
