The Government has declared spending at least $750,000 on the controversial Urewera raids and their long-running sequel - with some saying the final bill could be for millions.
A Weekend Herald request under the Official Information Act asked police, the Crown Law Office and the Legal Services Agency, which provides legal aid, for a running cost covering investigations in the lead-up to the early morning "anti-terror raids" on October 15, 2007, and the court cases against the 18 people charged.
The main trial of 15 defendants - who face firearms charges, with five also facing charges of participating in an organised criminal group - is now expected to begin in February.
The timing is subject to appeals against a decision to have the case heard by a judge alone and on the admissibility of some of the evidence, which is suppressed.
Police have refused to provide a detailed break-down of costs, but have provided an "aggregate figure" of $500,462.
This covers "certain direct operational costs" but excluding staff costs and a "significant amount of expenditure" which had not specially been coded to the case.
Figures released by the Crown Law Office showing costs to June 24 revealed $244,175 had been paid for two counsel to work on the case.
The Legal Services Agency has refused to disclose its costings, saying that the case is still before the courts.
Law Society president Jonathan Temm believes the combined police, Crown and legal aid bill will be "considerably higher" than the amount declared.
"By the time this trial is finished, it is likely to be the most expensive trial in our criminal history, because if this matter goes on to a full, three-month trial ... then the costs are going to be significant," he said.
Human rights lawyer Michael Bott, who represented one of the accused before withdrawing this year to focus on standing for the Labour Party, said he would not be surprised if the cost of the case ran to millions of dollars.
"It's going to be a hugely expensive case and the Crown wants to do their best to win - you don't throw a $10,000 saddle on a $500 horse.
"The Crown would be somewhat embarrassed if they were to walk away with nothing."
Wellington film-maker Errol Wright, whose feature-length documentary Operation 8: Deep In The Forest has been screening around the country, estimates the legal-aid cost at between $40,000 to $70,000 per defendant.
He believed the amount declared would "barely cover the cost of photocopying".
"I'd think the problem is that the case is still before the court and [the Crown] would argue that they're not in a position to disclose the information."