Brazilian giant Vale was yesterday attempting to correct the statement from Hartcher, who called for a “detailed report” on the matter.

The company said it was committed to working closely with the NSW government to ensure a “safe resumption of operations” at Integra but could not put a date on when it believed the mine would re-open.

“On Sunday, July 10 our monitoring had revealed that there were increased levels of gas in the longwall tailgate,” a Vale spokesman told ILN.

“The very next morning we contacted the district mines inspector and decided on a controlled withdrawal of employees from the mine.

“We’ve been working well with the Mine Safety Branch and unions with the end goal of getting the mine back into production.

“We’re happy with the progress.”

Hartcher, who attended the New South Wales Minerals OHS conference in the Hunter Valley this week, told ILN safety was one of the key priorities in his portfolio and he was keen to maintain zero harm in the industry.

“There is no point in having a mining industry unless it has a 100 per cent commitment to mining safety,” he said.

Hartcher said the department was working with the operator, the union check inspector, the mine's occupational health and safety committee and a site check inspector to "investigate and resolve allegations of health and safety issues at the mine [Integra] and restore the mine to full operations".

"I have been informed that whilst the mine is currently idle, certain essential employees have been permitted to enter the mine for inspections and pumping operations,” he said.

"I have requested a detailed report on this issue and will continue working with the department and mine operators to reach a satisfactory outcome."

The Vale spokesman said the company shared Hartcher’s focus on safety for all mining operations.

Integra’s general manager of operations Andrew Betts said all personnel were withdrawn from the mine in a safe and efficient manner.

“The safety of our staff is – and always will be – our first and foremost priority,” he said.

“We’re not prepared to jeopardise the ongoing safety of our employees and we’re entirely committed to working with the District Coal Mines Inspector and our employees to ensure that normal operations are resumed in a controlled and safe manner.”

Betts said a comprehensive recovery plan including risk assessments and procedures had been prepared and the situation was being monitored closely.

“We have a number of people dedicated to resuming operations and while we work towards a solution we’ve been able to access underground areas to maintain essential maintenance and water pumping activities,” he said.

The Vale spokesman confirmed that restrictive ventilation in the tailgate was the root of the problem but this was being investigated by a multi-stakeholder team.

“We’ve got a crack team of our people from onsite and from head office working on the recovery process,” he said.

The spokesman said all of the 280 employees would remain on full pay despite not working at the mine or being involved with the recovery process.

The company would use the opportunity for training of personnel, he said.

“It’s important that we look after our people and all our stakeholders,” he said.