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Beachgoers were left horrified after discovering the remains of a four-metre-long great white shark which had washed up on shore with half of its body missing.

The body of the three-metre shark was discovered by locals on Tuesday at Bridgewater Beach, near Cape Bridgewater, about 370km southwest of Melbourne.

Footage taken at the scene by local fisherman Ben Johnstone shows the dead shark lying on the sand.

The lower part of the animal’s body appears to have been torn apart, with only the upper part of its body remaining intact.

Killer whales are believed to have mauled the great white shark before its body washed up on shore.

Mr Johnstone told Daily Mail Australia he went down to the beach after a friend told him about the horrific discovery.

“I received a tip… that it might be there,” Mr Johnstone said.

“I (had) no idea what happened.”

Mr Johnstone, bait shop manager at Portland Bait and Tackle, said the shark could have been attacked by orcas searching for food.

He said the whales had been spotted near the beach a few days before the shark washed up on shore.

“It probably happened between the time they were spotted in the area… when they washed up on the beach,” he said.

“The carcass was pretty fresh when I got down there.”

Mr Johnstone said orcas feed on sharks to get some of the meat, but strangely do not consume the rest of the animal.

“They (killer whales) eat the livers of… white sharks, that’s the only part they eat,” he said.

“The head and pretty much everything else (remained) pretty much intact…they just want the livers.”

Parts of the shark carcass were taken away for testing.

Flinders University trophic ecologist Lauren Meyer told the ABC Killer whales as well as other whale species have a particular fondness for the internal organs of sharks.

“We see this with things like humpback whales, where (killer whales) come in and eat the tongue and leave the rest of the whale,” she said.

“We certainly see that they prefer the livers of white sharks, mako sharks, bronze and sevengill whalers, and even tiger sharks.”

Ms Meyer said orcas are known to hunt only for particular types of food and each group of whales behave differently, making them very difficult for marine experts to analyze.

“They are relatively elusive and each different group and ecotype has such specific behavior that it is difficult to draw conclusions about killer whales as a whole because they all act so differently,” Ms Meyer said.

Mr Johnstone said killer whales occasionally visit the Portland Bay area.

“Everyone knows it, and then they (the whales) will appear here…you won’t see them for a few years,” he said.

“For about two weeks they will stay there.”

He said it was the first time he had seen a shark carcass wash up on the beach, mutilated like this.

“I’ve seen it on TV before, but seeing it locally is pretty cool.”