The Pike River mine is "a crime scene" and an attempt must be made to re-enter it and seek evidence of what caused the explosions that killed 29 men, a parliamentary committee has been told.

The families of the victims also believe the remains of their loved ones may be in the 2.4km drift, the tunnel that leads into the mine.

The families were represented at a hearing of the commerce select committee on Thursday by their spokesman Bernie Monk.

"We want justice, no one has been held responsible and evidence can be found in the drift," Mr Monk told the committee.

"This is a crime scene and should be investigated as such."

The families have been fighting for re-entry since 2010 but the mine's owner, state-owned Solid Energy, considers it's too dangerous.

Also at the hearing was former chief inspector of mines Tony Forster, who supports the families' belief that safe re-entry is possible.

He's backing a report by mining engineers Robert Stevenson and David Creedy which outlines a case for safe re-entry.

"I would go in myself, and I'm not someone who takes reckless steps," he said.

Prime Minister Bill English on Wednesday ordered Solid Energy to stop work on sealing the mine and told it to investigate using remote-controlled equipment to examine the drift.

Questioned about that, Mr Forster said he believed it was feasible and the technology was being developed very rapidly.

"Technically, it can be done," he said.

"But if it discovers a body, there's going to be an almighty clamour about what happens next.

"We've got to have a follow-up plan."

Mr Forster said there could be bodies in the drift, because there were a series of explosions and if the men had been deeper in the mine they could have been blasted back into the entry tunnel.

He also said there was electrical switch gear in the drift that could help determine whether a spark caused the methane to explode.

The committee will consider the submissions and report to parliament on what it thinks should be done.