Police said the adult humpback was first spotted from a helicopter on Sunday, June 23.
The 18-metre-long whale was encumbered with about 200 metres of rope and fishing buoys.
The whale was next seen on Friday afternoon by people on a recreational boat off the southeast Victorian coast, about 4.5 nautical miles (8.3km) from Lake Tyers.
Water police deployed a specialist team with personnel from the state Department of Energy, Environment, and Climate Action, the Victorian Fishing Authority, and Parks Victoria, to attach a tracking device to the humpback.
On Saturday, the team were able to use smaller boats to get closer to the struggling whale and cut about 800kg of tangled ropes and buoys away.
Police used a crane to lift the tackle out of the water, ensuring it did not remain a hazard for other sea life.
"Normally police are searching for missing people or vessels in waterways, so this was a completely different kind of search for us," Inspector James Dalton said.
"The whale was so tightly tangled in the ropes and it wasn't travelling very far so we knew it was in real distress.
"To safely cut the ropes away, we needed to return the following day to ensure we could successfully remove enough of the rope that it could swim freely again.
"This was a huge team effort and we're so happy that it had a great outcome."
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