The United Nations has called on the federal government to reconsider its approval of dumping dredge spoil in the Great Barrier Reef Marine Park.
If not, the Great Barrier Reef could be listed as a World Heritage Site in Danger.
The United Nations Educational, Scientific, and Cultural Organization (UNESCO) sent draft recommendations on the reef to the World Heritage Committee on Wednesday night.
UNESCO is concerned a strategic assessment of the reef hasn't been completed despite recent approvals of coastal developments.
The body criticised the approval of the Abbot Point port expansion, which involves dumping three million tonnes of dredge spoil in the Great Barrier Reef Marine Park.
UNESCO said the federal government didn't properly assess alternatives to the dumping.
The body has asked the government to provide a new report proving that dumping is least damaging option and will not damage the reef's value to the World Heritage Committee.
"With a view to considering, in the case of confirmation of the ascertained or potential danger to its Outstanding Universal Value, the possible inscription of the property on the List of World Heritage in Danger," UNESCO said in a statement.
The report is due by February 1, 2015.
Comment has been sought from the federal and Queensland governments.
World Wildlife Fund for Nature (WWF) spokesman Richard Leck said it was the first time the UN body had commented on the dredging decision.
"UNESCO'S concern is shared by thousands of Australians and hundreds of leading scientists," he said in a statement.
"We call on the federal government to ban dumping of dredge spoil in the Great Barrier Reef World Heritage Area."
The Australian Marine Conservation Society said it was clear the Queensland and federal governments weren't moving quickly enough to protect the reef.
