Anti-1080 activists say poison was deliberately dropped on them on a West Coast farm today, while five protesters were arrested after interrupting the drop.
Around 20 protesters blocked an access road to Butlers Farm, south of Hokitika, to try and stop the poison drop going ahead this morning.
A smaller group breached a security cordon to reach the operational area and delay the planned drop.
Police were called about 6.45am and arrested five protesters under the Trespass Act and Biosecurity Act.
Police found nails laid on the access road to the operational area, which punctured the tyres of a police vehicle and a private security vehicle, Greymouth Senior Sergeant Allyson Ealam said.
After the delayed poison drop went ahead, the protesters told Newstalk ZB the poison was deliberately dropped on them.
The wife of one of the protesters, Justine Salter, said it was dangerous and illegal to drop the poison directly on people.
Last month, suspected 1080 pellets were left outside the Department of Conservation's West Coast conservancy office in Hokitika.
They were reportedly put there by 1080 protesters.
That protest followed the refusal by West Coast iwi Te Runanga o Makaawhio to give consent for any future 1080 poison operations.
Iwi groups were regarded as "affected parties" and asked to sign their consent to all 1080 operations within their area.
Te Runanga o Makaawhio deputy chairman Terry Scott said the Bruce Bay-based iwi had never been happy with the toxin and the runanga had now ruled it would no longer agree to its use. However, some drops had already been signed off -- including the biggest yet, planned for this winter to cover from Hokitika to Whataroa.