A Motiti Island hapu plans to call on the London Offshore Consultants as its witness in a possible Environment Court case, after the firm found the owners of the Rena grossly exaggerated the time and cost of getting rid of the ship.
Ngai Te Hapu accused the Crown of withholding the Marine consultancy's reports from the Waitangi Tribunal.
The Crown rejected the allegation.
Ngai Te Hapu spokesperson Buddy Mikaere said it did raise the findings with the tribunal.
He said he planned to contact the London Offshore Consultants for help, once the Bay of Plenty Regional Council released a report about resource consents about the wreck.
Mr Mikaere said the council was due to issue its report this week, which would indicate when it would go to the Environment Court.
He said once it knows that - the hapu would be able to build a case, which he hoped would include people such as those from the London Offshore Consultants.