The Queenstown Lakes District Council has received reports of members of the public placing poison within its parks and reserves.
tramping boots Photo: AFP
It follows a recent illegal drop of the highly toxic pesticide, Pindone, on Te Araroa Trail near Wānaka.
The council said it understood this had been done with good intentions, but it could have serious repercussions for animals including pets.
It said placing poisons on council land without the appropriate permissions was illegal and people could face prosecution for breaching the Reserves Act 1977.
Anyone travelling with animals along that section of the trail should keep them on a leash at all times.
Pindone has strict regulations around its use - it must be placed in certified bait stations unless laid by someone with the appropriate licence, it can't be laid on someone else's or council property, and any drop must be followed by warning signs for the next eight months.
The council's parks service delivery manner Clare Tomkins said it was vital rules were followed when laying poison.
"When poison turns up in unexpected areas it can have serious repercussions," Tomkins said.
"We know people want to do the right thing, but it's vital the correct procedures are followed."