A humpback whale off the Gippsland coast has been freed from a tangle of fishing lines, ropes and buoys that it may have towed all the way from Antarctica.

The adult whale was first seen by helicopter crews near Loch Sport on June 23 but wasn't found again until Friday afternoon when it was spotted near Lakes Entrance.

The Department of Energy Environment and Climate Action (DEECA) established an Incident Management Team to prepare for the delicate task of removing 200 metres of rope and line, as well as 11 floatation buoys that were attached to the whale.

Incident Controller Ellen Dwyer said specialised whale disentanglement crews, including staff from DEECA, Victorian Fisheries Authority and Parks Victoria, had attached a telemetry buoy to the whale on Friday, allowing them to track its location.

On Saturday morning, the crews caught up with the whale 24 kilometres off the coast of Marlo, where they began the disentanglement operation.

"By Saturday afternoon, the bulk of the ropes and buoys had been removed, allowing the whale to continue its migration along the east coast of Australia," she said.

"Unfortunately, a smaller section of rope could not be removed and was still trailing from the whale."

Difficult conditions

Ms Dwyer said the disentanglement crews worked in difficult conditions to free the whale.

"Our crews, with the help of a Victoria Water Police and Victorian Fisheries Authority support vessels, performed their work professionally and with the utmost care for the whale's welfare. Working in the open ocean during winter with one of the world's largest animals isn't an everyday job, but they have managed to achieve a great outcome.

"We place a heavy emphasis on training and crew safety, so it was great to achieve the desired result with everyone returning safely back to shore."

Ms Dwyer said DEECA was investigating the origin of the fishing equipment, with an initial analysis indicating that it was from an international vessel.

"It is possible that the whale became entangled during its summer feeding season off Antarctica and has been dragging it while it is undertaking its seasonal migration."

Abandoned, Lost, Discarded Fishing Gear (ALDFG) is a global problem affecting entire ecosystems and directly impacting animals such as whales.

Humpbacks migrate up to 10,000 kilometres each year from the rich feeding grounds near Antarctica to the warmer waters of northern Australia where they calve and mate.

Members of the public are encouraged to report all whale and dolphin incidents or strandings to the DEECA Whale and Dolphin Emergency Hotline on 1300 136 017.

Public in boats must stay at least 200 metres from whales and should not attempt to disentangle.

More information available at www.wildlife.vic.gov.au/wildlife-emergencies/whale-and-dolphin-emergencies