Australian company Evolution Mining has applied for another minerals exploration license in Northland.
The company is hoping to search for gold in the 4000 hectare Te Mata block between Kaikohe and Kaeo.
The mining giant operates seven mines in Australia and is already exploring the Puhipuhi area, north of Whangarei, where it's just completed six weeks of survey work.
If the new exploration permit is granted, Evolution will begin community consultation and a full environmental assessment of the Te Mata block area, the company's chief geologist Roric Smith said.
Minewatch Northland spokesman Tim Howard said last month locals should oppose the miners because of the risk they presented in an area with high mercury levels and heavy rainfall.
"It's the wettest area in Northland, it has the heaviest rainfall," he said.
"Any mining in this territory will be releasing oxidised toxic minerals into those water systems."
Puhipuhi people should be cautious about meeting the company's officials, because they will then claim they have community support, Mr Howard said.
Dr Smith said he was aware some locals didn't want a bar of mining, but the company was keen to give them as much information as possible about its plans.
Evolution is about to begin a baseline survey of mercury levels in streams and sediments in the Puhipuhi catchment, right down to the Kaipara Harbour.