Video has emerged of protesters touching Environment Minister Nick Smith's jacket as they yell at him.
The minister has claimed that protesters rubbed rat poison in his face and clothes and shoved him at a market in Nelson on Saturday.
The Nelson MP said a man and a woman had attacked him over a drop of poison bait that was to happen at the Brook Waimarama Sanctuary on Saturday.
"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," Smith said.
He said the pair left once police were called but continued threatening to poison him and his family.
Video obtained by the NZ Herald shows a man saying the bait is being dropped in his backyard, before wiping his hands on Smith's jacket.
A woman, holding a small blue block, can be seen in the background scribbling the block on Smith's table, and in the doorway of his caravan, before wiping it on Smith's jacket shoulder.
Smith flinches and tells the pair he will call police, prompting the pair to say "Oh you don't want it, but you're fine to do it in our backyard."
The woman puts the block down on the table, but continues her verbal barrage, and Smith tells a National volunteer to "call 111".
Smith tells the pair he is "more than happy to have a civil conversation", adding that the issue has already been resolved in court.
The video then shows the man saying "who runs the courts? You and your National w***ers." Smith can be heard chuckling in the background and smiles as the pair walk off.
As they walk away, the National volunteer tells the man: "You always have bad language. Why can't you just speak nicely and politely?"
He says: "We've tried nice and polite. [They] bulldozed over us and then dropped 26 tonnes of rat poison in our backyard."
Smith told Radio New Zealand yesterday that he did not recall meeting the pair before.
He said rat bait was thrown at his caravan.
That is not shown in the full 90-second video, which was shot by a bystander who came running after he heard people yelling.
The Herald obtained the footage on the condition that the protesters would not be identified.
A spokeswoman for Smith said yesterday he had laid a complaint with police.
"Police are following up and making inquiries. We intend to give an update when that position changes," a spokeswoman said.
There has been vocal opposition from some locals over the poison drop. The Brook Valley Community Group (BVCG) has strongly objected to the drop and Smith initially appeared to blame them for the incident.
BVCG lawyer Sue Grey told the Herald the pair were not affiliated with the group.