THE state's mining watchdog has suspended the exploration licence of Narrabri Coal, for building unauthorised tracks in the Pilliga Forest.
The long-wall mine, which forms part of Whitehaven Coal's operations, was found to be in breach of its licence following a state-wide compliance blitz in June.
More than a dozen hollow trees, which provide important habitat to native animals, were knocked down. The unauthorised paths also failed to divert around environmentally sensitive areas.
Resources Regulator head honcho Anthony Keon said the mine's actions showed a "comprehensive failure" to follow "fundamental regulatory obligations".
"The construction of the unauthorised tracks resulted in significant environmental harm," Mr Keon said.
"Exploration activities are subject to strict conditions in order to ensure appropriate environmental protections.
Citizen science group, the Leard Forest Node, has been monitoring the mine's "progressive incursion" in to the Pilliga forest for a couple of years, spokeswoman Anna Christie said.
"This is just the tip of the iceberg, the Narrabri Coal mine has been flying under the radar for several years," Ms Christie said.
She was glad to see meaningful action taken against the mine, rather than just "a fine and a tap of the wrist".
The suspension will remain in place until the mine conducts a full review of its compliance systems and can satisfy the watchdog that appropriate controls have been put in place.
Five other joint-venture partners also had their exploration licence suspended. The licence holders acknowledged the offending behaviour and offered to suspend all drilling and clearing activities.
The mine will be able to continue operating, however the suspension stops it from expanding or investigating new sites.
Whitehaven CEO Paul Flynn accepted that on this occasion the company failed to properly obverse its exploration obligations
"Based on our inquiries to date, the circumstances and communication failures that led to this outcome are unacceptable," Mr Flynn said.
"Whitehaven took immediate corrective action following the Regulator's site inspection, suspending all exploration activity and commissioning an independent audit and investigation to determine necessary corrective actions.
"The company is committed to ensuring all relevant issues are identified and addressed before exploration activities at Narrabri can resume and will continue to cooperate fully with the NSW Resources Regulator to achieve this outcome."