A group has gone to the Environment Court to ask that all the information in Trans-Tasman Resources' iron-sand mining application be made public.
The court action is led by Kiwis Against Seabed Mining (KASM), supported by Ngāti Ruanui and fishing company Talley's Group.
The Trans-Tasman Resources application to the Environmental Protection Authority (EPA) for consent to mine iron-sand from the seabed off Patea contains sections that are redacted (blacked out). They relate mainly to the content of seabed sediment, the modelling of a sediment plume resulting from return of sediment to the seabed, and to economic information.
The company has asked that anyone seeing the redacted material sign a confidentiality agreement, and not share the information with anyone.
The committee the EPA appointed to hear the application decided to allow the redactions.
KASM and its supporters say the public has the right to see the redacted information.
"We believe that asking everybody to sign an extremely restrictive confidentiality agreement in a public process is wrong," chairman Phil McCabe said.
If the Environment Court decides to make the redacted information public, KASM will ask the EPA to extend the period for public submissions on the application, to give people time to consider the new information.
The submission period has already been extended once, on the request of Ngāti Ruanui. It is currently due to finish at 5pm on November 14.
Nearly 10,000 submissions have been made so far.