Anti-1080 vandalism

Department of Conservation Director-General Lou Sanson says it is fortunate no one was hurt. Photo / Supplied

The wheel of a Department of Conservation contractor flew off while he was driving after the wheel nuts were loosened, in what the department believes is part of a spate of dangerous anti-1080 protests.

DOC has reported three cases to police where wheel nuts were tampered with.

It believes the vandalism was intended to intimidate workers and disrupt aerial 1080 pest control operations.

Director-General Lou Sanson says it is fortunate no one was hurt.

"We take any threats to DOC staff very seriously and are working with the police to find those responsible," he said.

DOC has not identified the two locations where the tampering happened in order to protect staff.

It has also told police of a case where 1080 baits were left in a DOC letterbox.

"People have a right to lawful protest, but I will not tolerate anyone putting my staff at risk as they go about their job of protecting our precious wildlife," Mr Sanson said.

State Services Commissioner Peter Hughes has backed DOC.

"This unacceptable behaviour is coming from a very small group of people and is rightly under police investigation," he said.

DOC's Battle for our Birds programme of aerial 1080 and ground-based predator control is being carried out over more than 750,000ha of reserve land.