Members of the public are being urged to report any sightings of a humpback whale entangled in fishing rope off Victoria's coast.
The marine mammal was spotted on Sunday by a helicopter crew bound for oil and gas platforms off Ninety Mile Beach, dragging up to 200m of ropes and lines and 11 buoys behind it.
The Department of Energy, Environment and Climate Action established an operation with other authorities to disentangle the whale if it was found.
Incident controller Ellen Dwyer said a helicopter searched for two days between Wilsons Promontory and Point Hicks but was unable to find the whale.
"A (department) specialised whale disentanglement crew, including staff from Victorian Fisheries Authority and Parks Victoria, were on standby at Lakes Entrance to remove the ropes and lines if it was located," she said.
The public has been warned not to try to disentangle the whale.
"These crew members are trained to deal safely with entangled whales," she said.
"After an assessment, the crew makes a determination on the best course of action."
Anyone who has seen the whale or buoys should call 1300 136 017.
Mariners have been advised to be cautious offshore of Loch Sport, as the whale could pose a navigational hazard.
