The High Court at Whangarei has begun hearing a dispute over beachfront land at Matapouri Bay.
Local Maori, backed by a community group, say a hectare of land was wrongly taken from a Department of Conservation reserve in a 1991 survey by the adjoining landowners, the Ringer family.
The family agreed in January to sell the disupted land to the Conservation Department for $3 million but is adamant there was no boundary error.
The plaintiffs - tangata whenua and the lobby group Friends of Matapouri - want the court to award exemplary damages and costs against the Crown.
They say they have had to pay for legal action over two years in order to put right the mistakes of the Crown, notably Lands and Survey staff.
The Crown says, however, that the plaintiffs are basing their case on a survey error back in 1893 that misplaced an original boundary peg - and the Ringers' later survey was correct.
