Resources Regulator executive director Anthony Keon said the actions breached the licence holder's activity approval and contravened the Mining Act.
"The construction of the unauthorised tracks resulted in significant environmental harm and demonstrates a comprehensive failure to observe fundamental regulatory obligations in relation to the exploration activity approvals," he said.
"Exploration activities are subject to strict conditions in order to ensure appropriate environmental protections. This includes avoiding environmentally sensitive areas and diverting around, or relocating, hollow-bearing trees to protect wildlife habitat.
"The actions by the licence holders warrant strong regulatory action and the Resources Regulator won't hesitate to use all the enforcement tools at its disposal to ensure that mining operators work strictly within their legislative obligations."
The licence holders have acknowledged the offending behaviour and offered to voluntarily suspend all drilling and clearing activities, as well as committing to completing a number of actions before recommencing exploration activities.
However, the regulator has determined that the nature of the breaches make it more appropriate to suspend the exploration licence, with the only activities permitted being those required to maintain a safe workplace or undertake environmental rehabilitation.
The suspension will remain in place until the licence holders conduct a full review of their management and compliance systems and can satisfy the regulator that appropriate controls have been put in place to ensure future compliance.
Whitehaven Coal CEO Paul Flynn said Whitehaven accepted that on this occasion it failed to properly observe its obligations in relation to its exploration approvals at Narrabri.
"Based on our inquiries to date, the circumstances and communication failures that led to this outcome are unacceptable," he 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."
A Whitehaven spokeswoman said the suspension notice related to an exploration lease area that was not associated with the operation and production from the Narrabri underground mine, which continued to operate normally.
