Video footage from Pike River a lack of apparent fire or blast damage is a compelling reason to grant victims' families' wishes to re-enter the mine's drift, the Labour Party says.
The footage, which emerged on Sunday, appears to show glasses that may have belonged to Ben Rockhouse, one of the 29 men killed in the explosive 2010 underground coal mine disaster.
"New Zealand has been told there's nothing but ashes and dust down there, they've been told that the drift can't be made safe to enter and investigate," his mother Sonya Rockhouse said in a statement.
"That's just not true, my boy is down there and if pallets and paper are intact then so is his body."
"[Prime Minister] Bill English needs to stop trying to hide from this... He needs to let our experts work with mines rescue to enter the drift and find out what happened down there."
The footage was taken by a camera lowered down a 126-metre bore drilled about a month after the explosions and into the deepest part of the West Coast mine. Broadcast by Newshub on Sunday, it shows undamaged wooden pallets and rubber hoses.
Labour leader Andrew Little says it provides a compelling reason for re-entry.
"This is creating even further doubt as to why the Government stubbornly refuses to consider a manned re-entry of the drift.
"National has promised an unmanned survey of the drift but they're even dragging their heels on that."
Mr Little said he had committed to safe re-entry of Pike and would "clear the technicalities that the Government hides behind".
At the end of April, re-entry calls hit the headlines when footage from a robot showed men working in the drift without sparking any blast.
However, Mr English has ruled out re-entry, relying on expert advice that it is too risky to go into the potentially explosive methane-filled drift.
"There's nothing actually new about the footage - it's been around for six or seven years," he told The AM Show on Monday. "It's all, I'm advised, has been assessed before as part of the decision-making around the mine."
He said it wasn't fair to say the families had been "lied to".
"What we know is there was a large explosion and 29 men did not come out of that mine. I think we should be a bit careful about assuming nothing serious happened. Something very serious happened in that mine."
The important thing now is whether it's safe to go in or not, which he says still isn't clear.
NZN / Newshub.