Northland's Te Uri o Hau Settlement Trust is denying that it botched the election process for new board members.
A former trustee, Mikaere Miru, has complained to the police that the trust improperly opened postal ballots without the returning officer.
But the trust's lawyer, Niamh McMahon, said the election was properly conducted.
She said trust staff did open the envelopes but removed only the voting papers relating to a Trust Deed amendment.
Ms McMahon said the voting papers for trustees were left in the envelopes and securely stored until they were delivered to the returning officer (another lawyer).
She said the returning officer had no concerns about the integrity of the election and did not consider it invalid.
Te Uri o Hau is a Kaipara-based sub-tribe of Ngāti Whātua, and received $15.6 million in a treaty settlement in 2002.