A native orchid has been wiped out and rare trees hacked down in the name of roadside maintenance in the Waipoua Forest Kauri Sanctuary.
The Waipoua Forest Trust (WFT) has accused New Zealand Transport Agency (NZTA) of putting kauri and other species under threat due to the mismanagement of the roadside on State Highway 12.
NZTA has admitted some maintenance practices along the road corridor have not been up to scratch.
Network manager Tim Crow said that while failures had occurred, "there is no evidence that the forest is under threat".
A report sent to NZTA and the Minister of Transport by WFT outlined serious breaches of a Highway Management Plan established in 2000 with input from WFT, local iwi Te Roroa, Department of Conservation and other stakeholders.