The inspectors have asked for more information about the accumulation of methane and how the company is managing the methane.

Although coal extraction and development has been suspended, mine personnel are permitted to carry out maintenance and other work underground.

Solid Energy chief operating officer Barry Bragg said the company remained confident its mines were operating safely.

“We will provide the required information to the department today and we will meet the inspectors again tomorrow,” he said.

“We are aware of no reason why the prohibition notice should not be lifted as soon as we have provided the information the department is seeking and expect to resume full mining activities shortly afterwards.”

Production at the Huntly East mine was down 7% for the March quarter to 8000 tonnes, due to harder mining conditions in some development and extraction blocks.

Huntly East underground mine underperformed in the last quarter of 2011 amid a temporary mine shutdown due to elevated methane levels, with production slipping 19% year-on-year.

The company said production at Huntly had been reducing over the last year, with the mine producing only 74,000t in the period ending December 31.

The company attributed the fall in production to harder mining conditions in some of the extraction blocks.

The $30 million Huntly North ventilation shaft is currently forecast to be completed on budget but the completion date has been pushed back three months to March 2013.

According to Solid Energy, it is due to longer lead times for the ventilation fans and systems and delays in resourcing the shaft sinking work.