A man who went into the Pike River mine after the explosion six years ago says he'd gladly lead a re-entry and it could be done tomorrow.

Victims' families gather each morning on the access road to stop the mine from being sealed, entombing the 29 men who died underground.

The families are desperate to see if they can recover bodies, but Solid Energy is resolute in saying this is not possible.

Harold Gibbens was among the rescue response when the mine exploded on November 19, 2010.

"We actually wanted to walk up there right there and then and do a search for bodies. But we had a job to do which was to put that seal up to make the mine safe," the former Mines Rescue man told Seven Sharp.

He'd gladly lead the re-entry, a job he says he's trained to do and has done in more perilous situations.

"It's an irrespirable atmosphere, it's inert, nothing can burn, nothing will light, nothing can explode. It's the most perfect opportunity to go in. It is safe, it is no different to a fireman going about his daily duties or a diver diving down onto a wreck" Mr Gibbens said.

"An exploratory team could walk up that drift and be in and out in about an-hour-and-a-half to two hours. That's all it would take - two hours.  You'd have volunteers, there'd be no cost in that. Mines Rescue would provide the sets and the gear. You could have a team in there tomorrow."

However, Environment Minister Nick Smith told Seven Sharp the Government's advice is that a re-entry cannot be done.

"You'll always be able to find some technical adviser in some part of the world who might say it's possible," Dr Smith said. 

"But all I have received is a one page letter from one in Australia who says that it might be possible, as compared with over nine reports, 650 pages of detailed risk analysis, $5 million spent on that work, and a conclusion that it cannot be done."