Hartcher reportedly told the Sunday Telegraph he was concerned Coal Services had the power to levy the coal mining industry without government oversight.

"Coal Services has been granted remarkable powers and operating functions in areas traditionally the reserve of state government but without the accountability and transparency to match them," he reportedly said.

"Whilst we support the arrangements for worker's insurance continuing unchanged, the lack of objective government oversight of a body which has taxing and spending powers and which the ICAC and Ombudsman are specifically prevented from scrutinising is of significant concern."

Hartcher is seeking to suspend exploration at NuCoal’s Doyles Creek prospect in the Hunter Valley while the granting of its exploration lease is being investigated by the state’s independent watchdog.

Last week, Coal Services appointed Lucy Flemming to the role of acting chief executive following Mark Coyne’s appointment as chief executive of Employers Mutual.

Flemming has held the position of chief financial officer of Coal Services since August 2010 and she will take up her new position on December 9.