Solid Energy has temporarily suspended mining at Huntly East Mine after inspectors found an accumulation of methane in a recently-mined area of the underground mine.
The decision was made last night following a Prohibition Notice issued by the Department of Labour's (DoL) High Hazards Unit.
Solid Energy chief operating officer Barry Bragg said the company remains confident that its mines are operating safely.
He said the inspectors have asked for more information about the accumulation of methane and how the company are managing that methane.
Although coal extraction and development had been suspended, mine personnel are permitted to carry out maintenance and other work underground.