The laying of poisoned bait in a Mt Tiger Rd forestry block has some local residents and pig hunters concerned they or their animals could unwittingly eat residual toxins.
Brodificaum-laced bait stations have been put through the Northland Regional Council-owned pine plantation and some neighbouring private land in recent weeks, the council's Biosecurity Projects Manager, Kane McElrea said.
Legally, the council must erect signs at entry points to its forestry land to warn the public poison is present. There is no legal requirement to notify people of the operation itself, Mr McElrea said.
But one man whose land shares a boundary with the forest believed locals should be given more notice about a poison operation, rather than just two signs on the kilometres long roadside boundary.
Andrew Randall said leaflets informing locals the poison operation was underway had been dropped in letter boxes in recent days. The leaflets were signed ''concerned neighbour''.
Mr Randall said he believed the poison, Brodificaum, was too heavy-handed when possums and rats could easily be "knocked over" by shorter lived toxins.
Brodificaum is an ingredient in most rat baits bought over a shop counter.
Mr Randall said it was known to have a long life after ingestion and could cause a "secondary kill" when scavengers ate poisoned carcasses.
He said he knew of hunters who had killed feral pigs in the vicinity in recent weeks.
"Pigs can't read signs and fences don't stop them," Mr Randall said.
"How would hunters know if a pig they got in the bush half a kilometre away hadn't eaten bait in the NRC block then moved into private property?"
Mr McElrea said the risk to people was ''extremely low'' and non-targeted animals - such as native birds, livestock, domestic pets and feral animals like pigs - were at low risk of being lethally poisoned or made ill by eating baits directly.
Bait stations greatly reduced the risk of poisoning non-target species, although they also reduced stoats and weasel after they ate animals that had digested the poison, Mr McElrea said.
"The Northland Regional Council does not use this toxin regularly, but it is used occasionally as an effective tool to control possums and rodents," he said.
Members of the public, hunters or dogs were not allowed in the NRC forest at any time.
The land is part of the 'Kiwi Link' Community Pest Control Area (CPCA) which involves landcare groups, forest companies and other agencies controlling pests across 13,000ha of largely privately-owned land between Parua Bay and the Ngunguru River.
The primary objective was to protect kiwi, Mr McElrea said.
Meanwhile, warnings have been posted by the Pukenui Western Hills Charitable Trust about a poison bait operation using cyanide to kills rats and possums.
Signs would indicate where the poison was placed and remind the public to stay on the walking tracks from September 2 until November 30.