Environment Minister Nick Smith has laid a complaint with police alleging protesters rubbed rat poison over his face and clothes at the Nelson market.
The Nelson MP has welcomed a drop of poison bait at the Brook Waimarama Sanctuary near Nelson on Saturday. It's being dropped to kill predators and protect native birdlife but there is local opposition to it and three people were arrested there on Saturday.
Dr Smith said a couple attacked him at the Nelson market on Sunday. They left once police were called but continued with threats to poison his family.
"The situation became quite frightening when it escalated from verbal abuse and throwing rat poison at myself and volunteers to physical shoving and rubbing rat poison over my face and clothes."
He said he was tolerant of peaceful protesters but the incident went too far and he lodged a formal complaint.