Opponents of a proposed seabed mining operation in Taranaki are demanding the release of blacked out pages in its resource consents application.
Trans-Tasman Resources has applied to the Environmental Protection Agency to mine 50 millions tonnes of ironsand a year off the coast of Patea.
Kiwis Against Seabed Mining (Kasm) chairman Phil McCabe said it was unacceptable that the company's application was shrouded in secrecy.
Trans-Tasman had a similar application turned down in 2014 because the EPA decided not enough consideration had been given to the environmental affects of the operation.
Mr McCabe told a small gathering of supporters in New Plymouth last night that the lack of transparency in the firm's latest bid was disturbing.
"This is a publicly-owned resource, it's in public space, this is a public process and there's no room for secrecy here. They've got to front up with the information and let people make a fair assessment."
The mining opponents fear life on the affected seabed will be destroyed and the plume created by mining will be detrimental to all marine life in the area, including foraging blue whales.
Mr McCabe said there was nothing new in the current application apart from the blanked out pages.
"TTR's come back with the same application that was prove two years ago that it wasn't acceptable by the EPA. The community stood up in bulk, en masse, to oppose it and now they've come back to drag us through the process again and we don't see much different about it this time around."
South Taranaki iwi Ngati Ruanui is also opposing the project.
Its kaiarataki, Debbie Ngarewa-Packer, said Trans-Tasman Resources was demanding that anyone wanting to see the redacted material sign a draconian confidentiality agreement which prevented getting outside advice on the contents, meaning access to the pages was meaningless.
"It's just not right in 2016 for us as iwi, and certainly for us as Kiwis, to be treated like this by a company who has never done any type of activity like this in our country, and to have such difficulty getting the type of information that normal companies, normal energy companies, bring in by the boxload."
Ms Ngarewa-Packer said Ngati Ruanui was very concerned about the application and had the backing of all Taranaki iwi.
"It's damn alarming when they have to put 40 plus pages into redaction ... basically blacked out.
"My management team in the environmental unit have 25 plus years' experience and they've never seen anything to this extent before."
In a statement, Trans-Tasman Resources said it was not being deliberately obstructive.
"A small proportion of the reports are confidential because its commercial and operational information; all of the redacted information is highly technical.
"Interested parties or their appointed experts are able to access this information by signing a confidentiality agreement - and the Department of Conservation, Taranaki Regional Council, the Iwi Fisheries Forum and commercial fishing groups have all done so."
The company said it wanted everyone benefit from project that would create 1600 jobs, 700 in the region, and generate export earnings of more than $300 million a year.
Public submissions on the project close on 14 October.