The receivers of Pike River Coal Ltd say they only have enough money to take recovery teams as far as the rockfall inside the mine - not far enough to recover bodies.
Mines Rescue Service teams have begun work to open the mine where 29 men died in a series of explosions from 19 November last year. The mine was put in receivership in December.
Receiver John Fisk, of PricewaterhouseCoopers, says they have set aside $1 million for the operation which started on Tuesday.
Mr Fisk says that should be enough for teams to travel 2km to the caved-in section of the mine. But after that, he can only try to negotiate for a buyer to recover the bodies.
He expects it will take the recovery teams until October or November to reach the rockfall.
The families on Thursday warned receivers the money must be found to complete the recovery attempt.
Spokesperson Bernie Monk told Morning Report the families are aware of the financial situation - which is why they have good legal representation.
Mr Monk says between possible action from the families and the union involved, the value of the mine must be plummeting, so it is in the receivers' best interests to resolve the situation.
"If the unions do what they do and if we do what we do, they've got nothing to sell. The value of the mine must be plummeting.
"This problem is never going to go away, so it's in the best interests to sit down with parties concerned - whether it's the Government or whatever and nut this out."
A lawyer for the men's families says the Government may have to intervene to force the mine's buyer to recover the bodies.
The Engineering, Printing and Manufacturing Union says the receivers' position is not good enough and risks the mine being internationally blacklisted - meaning no one would work there.