The taxpayer is footing the bill of almost $11 million for failed efforts to reach 29 dead workers trapped in the Pike River mine - but the victims' families say that money should be recovered from the sale of the mine.

Police have released their costs from the search, rescue and recovery operation after the explosion on November 19 which killed the miners and contractors - a total of $10,916,871 as at April 19, including invoices received from 232 suppliers. It does not include an additional $296,488 for police officers' allowances.

Prime Minister John Key told the Herald: "It's a significant expenditure, but I have always said as Prime Minister that the issue was never one of cost.

"It was a matter of doing everything we practically could to get the bodies of the victims out of the mine."

The largest single cost has been running the jet-engined GAG (Gorniczy Agregat Gasniczy) machine, which has been used to try to stabilise the volatile environment in the mine. This has cost more than $4.6 million.

Police have handed over operations to receivers for mine owner Pike River Coal, PricewaterhouseCoopers, which is now seeking to sell the mine. Assistant Commissioner Grant Nicholls said police would not be seeking to recoup any of the money they are paying out from an annual budget of $441 million for emergency response.

Spokesman for families of the dead mine workers Bernie Monk said that a figure could not be put on the value of lives, but the costs for 29 people were "chicken feed" compared with other complex rescue operations.

He said the operation paid for by police was essential in one day making the mine viable for business again.

Police recovering their costs through the sale of the mine would be "common business practice", Mr Monk said.

"Nobody is going to do something for nothing. If it wasn't for police doing what they did, there would be nothing to sell."

Mr Nicholls said the police focus had always been recovering the remains of the 29 workers, though making the mine safe for future use might be a "byproduct".

Mr Monk hoped that getting the mine up and running again would eventually lead to recovering the workers' remains for their families.