The team in charge of recovering the Pike River mine's drift, including the possible discovery of forensic evidence or human remains, needs more money.
But Pike River Recovery Agency chief executive Dave Gawn won't say how much.
Gawn has put a Budget bid before the Government, but would not say how much longer the operation could continue on the its current $36 million funding.
"We're still working within that $36m, but there are significant overheads," Gawn told Parliament's finance and expenditure committee this morning.
He also told the committee that the chances of finding human remains was "less likely".
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The agency had by this morning recovered 238m of the mine's drift, Gawn told the committee.
It is a further 1500m to an area known as Pit Bottom in Stone, where there could be forensic clues about what caused the explosion, and then an additional 500m to the agency's mandated goal of recovering as far as the roof fall area.
The last known location of the 29 men who died in the 2010 explosion was on the other side of the roof fall, but Gawn said that didn't mean human remains might be found on the side that the agency hopes to recover.
"I won't say 'never' because unusual things have happened with different explosions," he told the Herald after the committee hearing.
Gawn said the team had planned to recover 20m per shift and there were two shifts per day, but that had only been achieved once.
The poor rock quality meant that safety bolts had to be drilled into the roof to improve its stability, with 600 to 1000 bolts expected to be used in the first 500m of the drift.
"But beyond 500m, things get significantly easier in terms of better rock, more stability and less bolting. So there is a bright horizon beyond 500m."
He said the drift was being made as safe as possible, and short of a massive earthquake - the Hawera faultline runs through the mine - the likelihood of a roof collapsing on the workers was "fairly low".
Some items of interest had been recovered so far, but he would not elaborate beyond saying that they were not items of evidential interest.
"It would be great if there was something in there that provided some degree of accountability from a forensics perspective. I don't know if there is or not," he told the committee.
The current timeline was to make it to the roof fall area by the end of August, hand the mine back to the Department of Conservation by the end of November, and disestablish the agency in a year's time.
"But these dates are pretty spongy in terms of all of this uncertainty," Gawn told the committee.
Under questioning from National MP Mark Mitchell, Gawn said that the public seemed to think that the agency was recovering the mine itself, rather than just the access drift.
"That belief is still out there. I get it at virtually every public meeting," Gawn said.
"We have community updates. Our website is very up front – but some people hear what they want to hear."