Nearing the tragedy's fourth anniversary, Solid Energy and WorkSafe New Zealand are at loggerheads over whether Mines Rescue will be allowed to walk the 2.4km up Pike River Mine's entry tunnel.
State-owned Solid Energy bought the mine following the November 2010 explosion that killed 29 men, who still lie under the mountain.
The Greymouth Star reported on August 8 that the re-entry was now in doubt, even though $4 million had been spent during the past year prepping the explosion-damaged mine.
Documents released under the Official Information Act confirm Worksafe is comfortable with the re-entry process, but Solid Energy's own legal advice has put it in doubt.
Solid Energy chairwoman Pip Dunphy yesterday responded to claims it knew almost a year ago it could enter the mine, after TV3 revealed WorkSafe and Mine Rescue had advised Solid Energy it was technically feasible to do so.
Ms Dunphy said that after a preliminary risk assessment in August last year, the board's adviser recommended further risk assessment, aligned to industry best practice and involving more detailed examination. That was completed in July, she said.
''We are now in a stage of final oversight review by the management team and independent experts and are awaiting some of these last evaluations and individual experts' opinions,'' Ms Dunphy said in a statement.
When asked about the comment ''stage of final oversight'' and whether a decision could be due within weeks or months, a Solid Energy spokesman declined to detail any time line.
Solid Energy's new board was struggling with the requirement for a second escapeway, because there was only one way in and out - ironically, one of the main criticisms made after the disaster.
In the document dump yesterday, chief mines inspector Tony Forster said in October 2013 the current re-entry plan was ''safe and technically feasible''.
Last month he told Solid Energy chief executive Dan Clifford he was pleased ''Solid Energy has taken advice on the impact of the proposed health and safety legislation and is now in agreement with Worksafe that there is no legal impediment without a second egress''.
Mr Forster said the re-entry would involve rescuers walking up a rock tunnel - not a coal-mining operation - so there was no requirement for a second egress under current and proposed health and safety legislation.
Ms Dunphy said yesterday: ''It is Solid Energy's responsibility to make this decision and we will do so once we have all the information required to make a fully informed decision.''
The victims' families have repeatedly criticised decisions not to enter the mine, or deferments of decisions.
Pike River families lawyer Nicholas Davidson QC told Radio New Zealand yesterday he would like to know more about Solid Energy's legal advice on the re-entry.
''It's a matter of huge importance ... I don't know what they've been told,'' Mr Davidson said.
Ms Dunphy understood families would be frustrated with the time it was taking to complete the evaluations, which Solid Energy was trying to finish as quickly as possible, noting safety was the ''absolute priority'' before anyone entered the 2.3km tunnel.
State Owned Enterprises Minister Tony Ryall said Solid Energy had to be sure any re-entry was safe, and that decision was ultimately for Solid Energy to make, not WorkSafe.
WorkSafe reiterated Mr Ryall's comment, stating yesterday a decision to re-enter the tunnel was Solid Energy's. Solid Energy was criticised by the Engineering, Printing and Manufacturing Union, which claimed it had ''mishandled'' the situation, and it called for Mr Ryall to intervene.
EPMU assistant national secretary Ged O'Connell said all indications were that Pike River had been safe to re-enter for some time.
''The latest revelations suggest that the board of Solid Energy hasn't been focused on getting the job done. In the interests of the families and their community, we urge the minister to direct Solid Energy's board to make re-entry of the Pike River mine drift [tunnel] a top priority, or hand the job over to someone who wants to do it,'' Mr O'Connell said in a statement.
West Coast-Tasman MP Damien O'Connor said the plan to re-enter the drift was approved last year.
''By all accounts ... it was feasible and could be conducted safely. Of course, there will always be risks, [but] that applies to someone driving down the road,'' Mr O'Connor said.
