A UN mission to look into whether Queensland gas projects are putting the Great Barrier Reef at risk has been pushed back until next year.
In July, the United Nation's environmental arm criticised the Queensland and Australian governments for allowing gas processing on the doorstep of the reef.
UNESCO said it was concerned three processing plants being built on Curtis Island, near Gladstone, could affect the "overall universal value" of the reef.
It said it hoped to dispatch the mission this month.
But the coordinator of the World Heritage Marine Program, Dr Fanny Douvere, who will be part of the mission, now says it will visit from March 6 to 14.
The dates are still to be confirmed by the Australian government, she said in a statement.
In its July rebuke, UNESCO said the government had failed to tell it about approvals for the three plants, in breach of World Heritage guidelines.
The three plants are under construction on Curtis Island, inside the Great Barrier Reef World Heritage area.
They will convert coal seam gas, piped from the Bowen and Surat basins in Queensland's southeast, into liquefied natural gas (LNG) for export.
The federal and state governments have welcomed the mission, saying its members will be comforted by the conservation measures they'll see when they arrive.