Conservation Minister Nick Smith has given an assurance New Zealand's most protected conservation areas will not be mined, even though consents have been granted allowing companies to prospect there.
Eight prospecting consents for protected Schedule 4 land have been granted since 2010, when the Government backed down on plans to free up some of it up for mining after a public outcry.
The consents have been granted to prospect and explore for coal and other minerals in Coromandel in the North Island and the Paparoa National Park in the South Island.
Dr Smith says the permits do not mean mining will be carried out.
He told Radio New Zealand's Nine to Noon programme on Thursday companies prospecting for minerals often needed to survey a much broader area than where they planned to mine.
"It's not because they're proposing to mine in that area - Government's very plain that's no go."
Dr Smith says getting samples reveals information such as the proportion of gold or of contaminants helps the mining firms understand other areas.
Defence in parliament
Later on Thursday, the Government had to defend in Parliament its promise that no mining would take place on Schedule 4 land.
On behalf of the Prime Minister, the senior minister, Gerry Brownlee, told the House John Key stood by his promise not to let mining take place in Schedule 4 conservation land.
"I spelled out very clearly that we wouldn't be going into Schedule 4 land or World Heritage sites. The reason that survey is being undertaken, as I understand it, is because there are many other benefits that may flow from that data collection."
Mr Brownlee said it was hobby-type mining activities, such as panning for gold, being considered, not large-scale mining.
Miner has different interpretation
But one of the mining companies granted prospecting licences for the protected land says it believes it can still mine underground if it finds minerals.
Newmont Waihi Gold says it's legally possible to mine beneath Schedule 4 land, by building access on land close by and then excavating underground.
A spokesperson, Kit Wilson, says that's what the company hopes to do.
"We believe that under the Schedule 4 legislation and all the other current legislation it's possible to access ore bodies safely and also with due environmental considerations and therefore that's why we're exploring in those areas."
Environmental groups have doubts
Forest and Bird advocacy manager Kevin Hackwell says the plan poses environmental risks, such as mine collapses.
He says the Government needs to be clearer and shouldn't grant prospecting consents for land it doesn't want mined.
Anti-mining group Coromandel Watchdog and the Environmental Defence Society say they fear the companies would not be looking if they did not think they could change the Government's mind.
Environmental Defence Society chairman Gary Taylor welcomed Dr Smith's assurance but says more needs to be asked about exactly where the companies are heading with the information they gather. They're not just looking to contribute that knowledge to public good science," he says.
The Green Party is concerned the Government might reignite the debate over extraction in conservation land.