An anti-mining group claims Evolution Mining is drilling under conservation land at Puhipuhi but the Australian company refutes the allegation.
The Action Coordination Group said it was "shocked" earlier this week to find evidence Evolution was drilling directly under Department of Conservation (DoC) land and under a waterway on Puhipuhi mountain, 30km north of Whangarei.
The company says that is not the case and the protesters have got it wrong.
Supporters of the group found the drilling rig by hiking through neighbouring DoC land. They reported it was placed right on the DoC reserve's boundary and claimed it was aimed on a sharp angle to drill a core sample to 600m under the conservation land.
The group is a coalition of Ngati Hau groups and MineWatch Northland, and has actively opposed exploring and mining at Puhipuhi.