Coal Operations Australia was found guilty by the full bench of the NSW IRC in 2004 of occupational health and safety offences over the death of Anthony Carroll at the Wallarah colliery.

Eleven days later, Barry Edwards was crushed to death at the then Powercoal-owned Awaba shaft. Powercoal was convicted by the NSW IRC of failing to provide an adequate safety assessment system for the mine.

The two companies launched challenges in the NSW Court of Appeal over the findings, on the grounds it was unconstitutional to afford the IRC power to determine criminal liability for workplace death.

Chief Justice James Spigelman and Justices Keith Mason and Kenneth Handley did not agree and dismissed both cases on Monday.

They said there was nothing in the constitution to prevent state parliaments conferring powers on their courts “so long as they are not repugnant to or inconsistent with the exercise by those courts of the judicial power of the Commonwealth”

Chief Justice Spigelman said there was nothing in the Constitution to preclude states from legislating to employ non-judicial tribunals to determine issues of criminal guilt or to sentence offenders for breaches of the law.