Federal Environment Minister Greg Hunt failed to properly consider Indian mining giant Adani's poor environmental record when he approved Queensland's Carmichael mine, an environmental group says.
The Mackay Conservation Group says Adani was found guilty in 2013 by the Indian government of serious environmental breaches including illegally clearing mangroves, destroying tidal creeks and failing to get proper approval for some infrastructure.
Mr Hunt knew of these breaches, the MCG claims, but he instead relied on a self-assessment submitted by the Indian conglomerate in 2010 to convince him that their proposal to build the state's largest coal mine should go ahead.
"How can we trust this company with our land, with our water, with our reef when they've got such an appalling environmental record?" MCG spokeswoman Ellen Roberts told AAP on Wednesday.
"We're saying Greg Hunt failed in his duty to the people of Australia by choosing to ignore that environmental record and accept Adani's own assessment that they are a good operator."
The MCG this week amended its legal challenge to the $16.5 billion Carmichael project in the Federal Court to include the allegations against the minister.
Ms Robert said they want the court to force Mr Hunt to reconsider the project.
A spokesperson from the minister's office said Mr Hunt "made his decision in accordance with the requirements of the Environment Protection & Biodiversity Protection Act 1999".
They said it was inappropriate to comment further as it was before the court.
An Adani spokesman said numerous stringent approval processes had been followed, and the claim by MCG is "baseless, and reflects a concerted determination to oppose mining and mining approvals in the abstract".
