An India-backed mining consortium could shelve controversial plans to dump dredging waste in the Great Barrier Reef, with alternative sites on land being considered amid growing environmental concerns, Australia said Tuesday.

Environment Minister Greg Hunt said there was an "emerging option" that could see the consortium -- India's Adani Group and Australia's North Queensland Bulk Ports and GVK Hancock -- submit a proposal suggesting onshore dumping locations.

"There is an emerging option which I've said we'd welcome and consider on its merits," Hunt told the Australian Broadcasting Corporation.

"I can't put a time frame. It may be a month, it may be less, it may not occur. But we have encouraged and invited (another option)."

The minister's comments followed a report in The Australian Financial Review that the government-approved marine dumping plan would be abandoned to neutralise controversy over the possible damage it could cause to the World Heritage site.

Conservationists have said the dumping of three million cubic metres of material dredged from the seabed as part of a major coal port expansion at Abbot Point -- on the Great Barrier Reef coast in Queensland -- could hasten the natural wonder's demise.

The dredging, which was approved in January, will allow freighters to dock at Abbot Point, increasing the coal port's capacity by 70 percent to make it one of the world's largest.

The Greens party, which has criticised the reef dumping proposal, said its approval should be revoked.

"Onshore disposal would be a far better option environmentally and for the tourism and fishing industries, however the problems of increased shipping and export of coal to exacerbate climate change remain," Greens' environment spokesman Larissa Waters said.

Activist group Greenpeace "cautiously welcomed" the "good news", but warned there were still concerns.

"If the reports are true, the cheapest, most destructive option for expanding Abbot Point may have been taken off the table -- but the threat from coal industry expansion plans is still urgent," spokesman Adam Walters said.

The Australian Conservation Foundation's climate change campaigner Abigail Jabines said the dredging itself was a danger to the reef.

"Even if the spoil is not dumped at sea, the dredging itself has environmental impacts, with dredge plumes damaging sea grass meadows, which are an important habitat for turtles and dugongs," she said.

The number of dugongs -- a long-living but slow-breeding mammal -- are declining in reef water although species such as humpback whales and loggerhead turtles are growing, a Great Barrier Marine Park Authority report said last month.

The same report warned the reef was "under pressure" from climate change, poor water quality from land-based run-off and the impacts from coastal development with the outlook for the natural wonder rated "poor".

UNESCO in June deferred listing the reef as in danger and gave Australia until February 1, 2015 to submit a report on what it was doing to protect the biodiverse site.