Police involved in the Urewera dawn raids had still not fully co-operated with the agency investigating their actions five years after the controversial operation.
Recent briefings from the Independent Police Conduct Authority to Justice Minister Judith Collins said investigators still wanted to interview officers involved in the raids which saw roads blocked and homes searched by armed police.
The difficulties in securing an interview will not stop the release of the IPCA's report into the 2007 raid, which is expected just weeks after the final legal hurdles were removed this week. The Supreme Court rejected an attempt to appeal against firearms convictions by the "Urewera Four".
The four, including Tuhoe stalwart Tame Iti, were the only people left facing charges of the 17 arrested in connection with the October 2007 raids. The police sought charges under the Terrorism Act after filming weapons training in the Urewera Ranges but were left with a handful of firearms charges after the courts ruled evidence to be inadmissible.
Briefings from the IPCA to Ms Collins in June and October last year raised the desire to conduct interviews with the police officers involved in the raids.
Ms Collins was told "further information is being sought from other officers involved in the termination of the operation".
The IPCA does not explain why there was a delay and offered to take statements from the officers by written statement or interview.
Papers released under the Official Information Act also showed the Government was under pressure from the United Nations to satisfy international questions over the raids.
Officials at the Ministry of Justice warned Ms Collins that delays in bringing the prosecution to a close "may result in some criticism".
The UN's human rights committee had previously been told the trial would be finished by 2011, along with the release of the IPCA report - neither of which has happened.
A Law Commission project inquiring into "public safety and security" was also cancelled, despite the UN having been told it was under way.
Tuhoe chief negotiator Tamati Kruger said he had talked with Sir David Carruthers, chairman of the IPCA, about a month ago and was told police would have four weeks to respond to the report's findings. He said he expected it would be released in May.
"We're excited by the fact that in the next four weeks this will be public and we're looking forward to reading it," Mr Kruger said.
"I think the New Zealand public has a feeling something went wrong here and we're all looking forward to seeing if that's the view of the Independent Police Conduct Authority - or do they vindicate?"
A police spokesman said the force would not comment on an IPCA inquiry.