An Anglo American spokeswoman said the company was fully cooperating with the Queensland government's Board of Inquiry into safety in the state's coal mining industry to determine the cause of the ignition of methane at the mine.

"It would be premature for anyone to pre-empt this process by speculating about the significance of information or incidents outside this inquiry and other investigations underway," she said.          

"We want answers as to why an ignition of methane occurred at Grosvenor mine, and we understand that everyone else does too.

"Through our own expert investigation and other inquiries underway, we know we will learn more to help us to improve the management of methane and safety in underground mining.

"We will share the results of our technical investigation with our workforce as soon as possible as well as additional controls that we will put in place to prevent this kind of incident occurring again."

The spokeswoman said as a global mining company with a vision of zero harm, Anglo American had extensive safety management systems and processes in place across all operations, which drew on international best practice.

"Safety is a core value for Anglo American and always comes first," she said.

"Underground mining is technically complex and highly regulated, with the coal mining Safety and Health Act enabling a high level of oversight and scrutiny of operations by the Queensland Mines Inspectorate and union statutory officials.

"Mine Record Entries … are reports that issued by the Queensland Mines Inspectorate or union statutory officials [Industry Safety and Health Representatives] following mine site inspections.

"They are published at sites and made available to all coal mine workers. Anglo American comprehensively responds to all MREs, directives and high potential incidents."

The spokeswoman said that in the two years between July 1 2018 and June 15 2020, the Inspectorate issued 2872 directives and substandard condition or practice notices relating to safety and compliance at Queensland mines and quarries. Grosvenor mine accounted for just 13 of these - less than 0.5%.

"We comply with any directives that are provided following inspections at our mines," she said.

"As the largest underground coal miner in Queensland, we have been at the forefront of technical innovation and have invested significantly in technology to improve safety in our mines, including additional methane detection equipment, digitisation to improve underground communication and automation of equipment.

"We will continue to prioritise work in this area, and we expect that emergent technological solutions will form part of our response to the incident.

"Our underground mines are located in a methane-rich area of the Bowen Basin, and we proactively manage this through a number of measures, including the draining of gas before and during mining and the installation of extensive ventilation infrastructure.

"We intentionally exceed the regulatory requirements at our mines by having a higher number of methane sensors and have additional controls above what is specified in the regulations.

"Many of the HPIs reported to the Mines Inspectorate were from methane exceedances picked up by these additional sensors, and are a demonstration of the strong reporting culture and compliance within our operations."