An Australian federal court on Wednesday revoked the government's environmental approval for the Adani Group's Carmichael mine in north Queensland, one of the world's biggest coal mines under construction.
Environmentalists say the project threatens the World Heritage-listed Great Barrier Reef.
While environment groups hailed the decision, Adani Mining said the decision to revoke approval for the A$16.5 billion (US$12.2 billion) project was the result of a ''technical legal error'' related to documents on the conservation of two vulnerable species in the Australian outback.
Environmental groups had challenged the government's approval of the mine on the basis of the enormous amount of greenhouse gases it would create, its impact on vulnerable species and Adani's "poor environmental record".
They also have protested against its impact on the Great Barrier Reef, one of the world's most biodiverse marine areas, because of the coal would have to be shipped out of a nearby port, as well as the damage caused by climate change.
The court said it halted the project because of problems in the approval process, the Environment Department said.
The group said the yakka skink and an ornamental snake weren't presented by the environment department when completing its approval for the mine-and-rail project in central Queensland state, a year ago.
The case brought against mine alleged that environment minister Greg Hunt had approved the project without regard for conservation advice for the two endangered species.
''The conservation advices were approved by the minister in April last year, and describe the threats to the survival of these threatened species, which are found only in Queensland,'' Sue Higginson, the principal solicitor at the Environmental Defenders Office NSW, said.
The court has ruled the environment minister, Greg Hunt, ignored his own department's advice about the mine's impact on two vulnerable species, the yakka skink and the ornamental snake.
The decision leaves Adani, which has already halted work on the project without the legal authority to begin construction.
Adani, however, expects to clear the roadblock as the conditions imposed on the existing approval are technically robust and appropriate.
The Indian conglomerate said it was committed to developing the project and that it would ''await the minister and his department's timely reconsideration'' of its development application.
The department said there was a possibility that the advice it provided to Environment Minister Greg Hunt before he made his decision "should have been provided in a particular manner".
"This is a technical, administrative matter and to remove this doubt, the department has advised that the decision should be reconsidered," it said. "Reconsidering the decision does not require revisiting the entire approval process."
It said it expected it would take six to eight weeks to prepare its new advice and supporting documentation and for Hunt to reconsider his decision on the mine.
"Without pre-empting a final decision about the project, the department expects that it will take six to eight weeks to prepare its advice and the supporting documentation, and for the minister to reconsider his final decision," the department said on its website.
Adani said Wednesday it was committed to ensuring its mine, rail and port projects in Queensland were developed and operated in accordance with Australian laws, including strict environmental conditions.
"It is regrettable that a technical legal error from the Federal Environment Department has exposed the approval to an adverse decision," the company said in a statement.
"We have been advised that, because certain documents were not presented by the department in finalising the approval, it created a technical legal vulnerability that is better to address now."
Adani said it would await the government's reconsideration of the approval, adding it was confident the conditions imposed on the original consent were robust and appropriate.
The company said it was in the fifth year of development and approvals for the project and "the need to finalise these approvals and timelines is critical".
The mine is estimated to provide electricity for up to 100 million people in India and generate thousands of Australian jobs.
But the development proposes massive open-cut and underground coal mining some 160 km northwest of Clermont in central Queensland, as well as a 189-kilometre rail link.
It is forecast to produce 60 million tonnes of thermal coal a year for export, which environment groups say would create vast amounts of carbon emissions that are blamed for global warming.
Adani's Carmichael mine in north Queensland has been bogged down by environmental concerns from the beginning.
Traditional land owners and various environmental groups, including Environmental Defenders Office NSW, have been opposing the project over pollution concerns and the threat its port project and washeries would pose to the Great Barrier Reef.