The Waitangi Tribunal has faulted the Crown over the way it handled settlement negotiations with two tribes in the Wellington region.
It's issued an urgent report on the Treaty package for the Port Nicholson Block Settlement Trust - an arm of Taranaki Whanui.
The Crown had told the Trust that no property within its territory would be offered to another iwi, Ngati Toa - apart from the Wellington Central Police Station.
But the Waitangi Tribunal has found the Crown did offer Ngati Toa the first right of refusal to buy state properties in Wellington, including in the CBD - and now says those offerings should be re-negotiated.
It also points to flaws in the way the Crown conducted the process, and says different teams of officials hardly talked to each other - adding that there was a lack of clarity in the language they used.
The tribunal says the Crown's approach caused confusion, which could have created new grievances.
Meanwhile, the Port Nicholson Block Settlement Trust has welcomed the inquiry's findings.
Professor Sir Ngatata Love says their dealings with the Crown have been extremely disappointing and frustrating.
However, he says Taranaki Whanui continue to fully support Ngati Toa in their pursuit of a fair and just settlement with the Crown.