Police commissioner Mike Bush has confirmed that manslaughter charges are possible after evidence is collected in the Pike River re-entry.
"Our case is open, and everything will be based on evidence," he told Newshub. "The purpose of us being involved here is, if it's safe, to ensure that we take advantage of any opportunities to examine forensic evidence."
His comments come after the Government announced it will go ahead with a plan to re-enter the Pike River mine after reviewing three options.
Pike River Minister Andrew Little has been considering whether it's safe to send experts into the drift - the 2km long shaft which leads to the mine itself. The 2010 disaster claimed the lives of 29 miners and contractors.
Mr Little received a report from the Pike River Recovery Agency late last month following nine months of research in which three "safe and feasible" options to go into the drift were drafted.
He confirmed the Government has approved the "single entry" re-entry plan, which means re-entering the mine through the existing drift design.
The other options included:
- Drilling a second tunnel at the end of the drift, close to the mine workings;
- Drilling a large borehole part way down the drift for both ventilation and emergency outlet
"All options presented to me required additional funding," Mr Little said in a statement. "This week, Cabinet approved an additional $14 million of funding for the single entry option to bring the total cost of the project to $36 million."
He said the first major task to re-entry - the breaching of the 30m seal - will likely commence in February next year. Over several weeks, he said, additional small boreholes to assist pumping and ventilation will be drilled.
"I've built confidence very quickly in the advice I've received," he said in a Wednesday morning press conference. "I've observed what they've done over a period of time and I've had total confidence in the advice. This hasn't been a difficult decision to make because of that."
He said there is a possibility of recovering bodies, as there were two survivors from the disaster, one who came from the far end of the drift, so there could possibly be other bodies at that end. He said there will be an effort to "get whatever forensic evidence we can".
The previous National Government said the mine was too unsafe to re-enter and was prepared to seal it off. But Mr Little said none of the reports he received about re-entry said it couldn't be achieved, and that all it required was managing the hazards and safety requirements.
Anna Osborne, widow of Pike River miner Milton Osborne who died in the explosion November 2010, said it's "a fantastic day for the Pike River families".
"This has been eight years in the making, and we fought really hard to get to where we are today. We have the coalition Government to thank for that, as well as the very competent staff that the Pike River Recovery Agency have employed."
The Pike River Recovery Agency was established within 100 days of the Government coming into power, to manage the Pike River recovery project. Its first task was to provide Mr Little with advice on whether re-entry wold be possible.
Dave Gawn, who was appointed as the head of the Pike River Recovery Agency last year, said "this is only the start". He said there's still a lot of work to do, and echoed Mr Little's sentiment that there is still a lot of questions about re-entry that need answering.
Greymouth Mayor Tony Kokshoorn told The AM Show on Wednesday that eight years of heartache has balanced on the Government's announcement. He said the disaster defined his career, adding that it's a sadness he'll take to the grave.
New Zealand First leader Winston Peters promised Pike River victims' families in December 2016 that he would be the first person to re-enter the mine drift. He reaffirmed his pledge in June.
Police have not ruled out criminal charges being laid based on any new evidence that emerges after the re-entry takes place. Garner said the police will be on standby with their forensic team.
Families of the victims blasted the police in September after an investigation was launched into whether police were responsible for a second explosion at the mine.
The investigation probed whether a conveyor belt inside the mine was started up, which could have created a spark which ignited methane and ended all hope of finding any of the men inside alive.
Official documents showed authorities considered turning the belt on to give survivors a chance to ride it out, although they cautioned it was a "moderate risk" which could ignite a secondary explosion.
"The families may get answers, but they also may not," said Garner, considering the ramifications of re-entry.