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.
"With this powerful new evidence, it is clear that the company is drilling core samples away from their base on private land, beneath a waterway and underneath the DoC native forest," said MineWatch Northland spokesperson Tim Howard.
"This is the first substantial confirmation we have received that one of Evolution's and the Government's real targets for potential mining here is protected conservation land."
But Evolution's New Zealand project manager and senior geologist Jackie Hobbins said the company is not drilling on or under DoC land and is conducting its work in compliance with mining laws.
"The ore bodies we are targeting are vertical or near vertical so it is standard to drill inclined holes in order to effectively test multiple potential targets," Dr Hobbins said. "In addition to the extensive baseline environmental study we conducted, Evolution has environmental controls in place that are routinely monitored, including procedures to ensure that no drilling fluids enter any waterways.
"All holes are cased to 150m, which is well below any waterway."
The first explorative borehole of 10 was completed on Tuesday and will be sealed and capped.
"As per our drill plan, our next drill hole will be targeting the opposite direction to the first drill hole.
"The results from this drill programme will inform any decisions regarding our next steps," Dr Hobbins said.
Evolution earlier said even if high quality gold or silver were found in viable quantities, mining would not start in the next five years, if at all.