"There are people getting away with it. I mean I could take you into the forest and show you shooting spots, you'll find a stash of feathers on the ground."
DoC is investigating Ngapuhi Runanga chairman Sonny Tau after kukupa was found in his possession.
The dead birds, allegedly from the Ngai Tahu area, were allegedly found hidden inside Mr Tau's jacket as he was due to board a plane at Invercargill Airport last week.
Mr Tau - who stood down from his role as head to Ngapuhi Treaty negotiator Tuhoronuku over the furore - has not responded to repeated requests from the Northern Advocate for an interview since issuing a statement last week apologising for his "mistake".
Mr Harris said illegal hunting and possession of the bird was difficult to monitor.
"From a law and enforcement view, and I'm not in law and enforcement, it is quite hard to track."
The conservation board serves an advisory role to DoC, and offers community perspectives on conservation management issues for the region.
DoC could not comment on Mr Tau's case while investigations were under way.
However, statistics released to the Advocate showed there had been 47 individuals convicted for killing or possession of kukupa in Northland since DoC was established in 1987. There had been 15 convictions since 1998, but none since 2007.
A DoC spokeswoman said most national convictions for killing or possession of kukupa were for offending that occurred in the Northland region.
"DoC understands that unlawful take of kukupa still happens in Northland but there has been a reduction in incidents in recent years following the kukupa advocacy programme and the rahui put in place by iwi."
When asked why there had been no prosecutions since 2007 she said DoC relied on information from the public about illegal hunting and also monitored areas where unlawful activities were known to have taken place.
But she would not comment further on that or on how DoC undertakes operational compliance work so was unable to say how many rangers monitored forests or what forests were monitored.
Meanwhile, Ngapuhi elder Kingi Taurua said the alleged actions of Mr Tau "tarnished the iwi" and at a meeting of iwi members held on Tuesday it was decided a group of elders needed to travel to the South Island to apologise to the Ngai Tahu iwi.
"We need to restore the mana of Ngapuhi. There's lots of news that some Ngai Tahu are really disappointed. Ngapuhi had no right to take taonga. How would Ngapuhi feel to have taonga taken from us?" Mr Taurua said.
Mr Taurua said the incident made him feel "whakama" (embarrassed).
"If it was only focused at a specific group, Ngapuhi wouldn't go.
"But because Ngapuhi has been mentioned it is only right we go down. We do not condone this," he said.
Mr Taurua said he would hold a meeting with a group of elders to discuss when they would travel down.
There have also been calls for Mr Tau to resign as head of the Ngapuhi Runanga.
But Te Runanga-a-iwi o Ngapuhi said while it was disappointed with Mr Tau's actions, and it did not condone them or the taking of kukupa, he would remain as chairman.
The runanga would not comment further while the DoC investigation was ongoing.