Work to stabilise the Pike River coal mine has been delayed a second time by dangerous gas readings, receivers say.
The stabilisation plan, which involves sealing the portal into the mine, is seen as the first step towards recovering the bodies of 29 men killed by a series of explosions in November.
Its start date was pushed back after receivers announced high levels of carbon monoxide had been found in the mine on May 26.
PricewaterhouseCoopers receiver John Fisk today said while those readings had decreased, it still wasn't possible for work to begin.
Gas experts were assessing the readings at the mine daily, he said.
"Safety is our first priority and in this regard we will not allow the work in the portal to commence until we have sign off from Mines Rescue and the other experts."
Sealing work at a vent shaft into the mine may contributed to a decrease in gas levels, Mr Fisk said.
It was hoped this trend would continue - though atmospheric conditions in the area were also expected to impact on gas levels in the mine, he said.
The further delay provides more heartache for the families of the 29 miners.
They launched an effort to take over responsibility for recovering the bodies of their loved ones after the stabilisation delay was announced.
Lawer Nicholas Davidson QC said families did not trust receivers to recover the dead.
He said experienced mines rescue experts had offered to work with families to establish a credible plan for re-entering the mine.
"From the moment police handed the mine over the receivers, nothing has happened.
"We are not waiting any longer for the company or the receivers to produce such a plan because they have done nothing... the only interest they have is an economic one.
"Families are going to ensure a plan is now developed by someone other than the receivers or the company."
Mr Fisk said receivers had been working to stabilise the mine for two and a half months.
That work had been delayed by mines rescue staff having to commit to other jobs and bad weather, he said.
"It's not the case that we have deliberately slowed any process down or deliberately sat on our hands. That's definitely not the case.
"As I've always said our focus is very much on getting the mine stablised. Until you've achieved stability you can't achieve recovery. You can't go into a mine that is not stable."
He called for families to work together with receivers to come up with a recovery plan.