An independent investigator still believes the best chance of prosecution over the Pike River disaster is by physically going back into the mine.
Police made the surprising announcement on Friday to drill 10 new boreholes - but now there are questions if it'll help the investigation at all.
A video camera down a borehole shines the slightest of light into the darkness of Pike River Mine.
Now there's doubt as to whether new boreholes will help the ongoing criminal investigation.
"You can't gather DNA from a borehole, you can't take samples, you can't make accurate measurements, you can't look at the other side of objects or shift something out of the way," Pike River independent investigator Richard Healey said.
Healey has investigated the disaster on behalf of some of the victims' families. He believes the best evidence would be found on foot.
"In order to conclusively establish what happened at Pike River and stop a similar event happening again, the mine needs to be reentered," Healey said.
Police made the surprise announcement this week to drill 10 boreholes back into the mine, focusing mostly around the A and B headings or roadways and the cross cuts that go between them.
Police haven't revealed just how they'll carry out the drilling work.
"They should bang down a couple important boreholes, analyse that data, and then make a decision about where to place the rest of the holes," Healey said.
The decision to drill again after finishing earlier this year has angered some families.
"They've sealed the mine up, they've taken all the equipment off the hill, now they're going to go and do it all over again," father of Pike River victim Bernie Monk said.
The Government sealed the mine shut last year and won't go back.
"Well drilling boreholes is pretty much low risk and doesn't put any lives at risk, it goes down into wherever the Police want to go to and they send scanners down and have a look around," Pike River Re-Entry Minister Andrew Little said.
Other families are happy to let police keep investigating through the boreholes.
But images from the previous drill program paint a bleak picture.
"Heavy thick steel bent over in an almost 180-degree shape, so the force of the blast was really quite strong," Pike River widow Anna Osborne said.
What caused that blast is question number one.
"Police remain absolutely committed to finding out as much as humanly possible as to what led to the first explosion at the mine," Detective Superintendent Peter Read said.
The final borehole drilling program is due to finish by the end of March next year.
