A trail of cyanide found in the Tangowahine area could have put lives at risk, the Northland Regional Council says.
Council staff have cleaned up 27 tablespoon sized drops of cyanide paste on a 2km stretch of Kaipara forest road, in a privately-owned section.
The council's hazardous substances specialist, James Mitchell, says it's likely the trail of poison was used to kill possums for their fur.
He says those responsible have acted illegally because they didn't get permission from the owner, and could have risked animal and human lives because no warning signs were posted.
