US miner Peabody Energy had a culture of “cutting corners” and pushing safety boundaries before the spontaneous combustion of its best Australian mine, according to evidence given by former employees to a class action lawsuit that has accused the company of misleading investors.

Nine confidential witnesses, including one former safety inspector with the Queensland government’s mines inspectorate, have told a US court of errors in gas management at Peabody’s North Goonyella coking coal mine prior to it catching fire in September 2018.