He used the money he stole for a variety of purposes, including travel and accommodation, luxury clothing, cosmetic surgery and the purchase of a vehicle.
1 News has reported that Te Ahuru called himself Wallace the Tory on social media and posted photos including a $130,000 BMW, drinking champagne and dining with former Prime Minister Sir John Key.
Serious Fraud Office director Julie Read said: "Mr Te Ahuru deceived the custodian of one of the most historically significant places in New Zealand. His offending has caused reputational damage to the Waitangi National Trust which is the recipient of government grants and private donations."
Te Ahuru was remanded in custody to reappear for sentencing on November 30.
A governance expert has told TVNZ's Te Karere that fraud can be difficult to detect, and multiple levels of protection are needed to guard against this type of theft.
Pita Tipene said he was shocked by the theft, as was the rest of the board of the Waitangi National Trust.
Tāmaki Makaurau MP Peeni Henare said he was glad the crook had been found out.
"The challenge now is to restore the reputation of the trust," Henare said.
