"In the last six years or six years before that vote, there were over 100 consultation hui with Ngapuhi, at home, across the country and in Australia.
"There were three rounds of consultations and at the end of that consultation there was a democratic process of voting offered - those were the results."
Mr Tau said the vote showed the majority of Ngapuhi gave Tuhoronuku mandate to carry out Treaty settlement negotiations, despite the fact only 23 per cent of the 29,389 people who received voting packs had voted - of those 6759 people, 5137 gave their mandate to Tuhoronuku.
"The fact of the matter is they were given every opportunity to participate and [of] those who chose to participate, 76.4 per cent voted and gave approval."
The three negotiators selected are Alison Thom, of Ngati Horahia and Ngati Toki descent, a former chief executive of Te Runanga A Iwi O Ngapuhi who has held a senior management position at Te Puni Kokiri, the Department of Corrections and the Ministry of Education; Joe Davis, of Ngati Kopaki descent, a specialist in Maori development who for 15 years was a researcher of his iwi's claim, and for the past five years has been a settlement negotiator; and Hemi Toia, of Te Mahurehure descent, who is a former chair of Taitokerau Forests Limited, and has lectured in accountancy and Maori resource management at Victoria University and at the University of Auckland.
Mr Tau said he had "no doubt" that the processes used by the Crown, in recognising Tuhoronuku as the claim negotiation body, were fair.
"I am certain that it was robust and fair, I'm very certain about that " he said.