An application to WorkSafe for a stay in sealing the Pike River Mine has been denied.
Twenty-nine men died in a series of explosions in the West Coast coal mine in November 2010.
Solid Energy, which bought the mine assets two years later, resumed work on Monday to permanently seal it.
Three of the victims' families have asked WorkSafe to review the closure plans, saying the mine could still contain important evidence.
But their lawyer, Nigel Hampton QC, told Checkpoint with John Campbell this evening that the existing notices for the mine still stood.
"They variously require: one, the temporary seal to be improved by the end of this month and, secondly, the permanent seal sealing the actual mine to be in place by February next year."
Mr Hampton said he was yet to confirm his instructions with the families but the next step could be appealing the decision to the District Court.
"We'll be setting up an argument as to the unreasonableness from the families' perspective, both as to recovery of bodies and finding forensic material possibly in relation to the explosion itself."
He said a decision on a review of the dismissal of charges against former Pike River chief executive Peter Whittall could be affected by the mine being sealed.
"If they, say, were reinstated, then for evidential purposes access to that mine might be important still."