A four-metre (13ft) great white shark was found dead on an Australian beach after biting off more than it could chew. It had a sea lion stuck in its throat.

shark chokes on sea lion
Shark washed up after choking on a sea lion.WA Fisheries Department

The shark was washed up on Coronation Beach in Geraldton, Western Australia, two days after it was filmed thrashing around just one metre from shore.

An investigation into the shark's death was launched by the Department of Fisheries after it was found.

The department said in a statement: "A white shark found washed ashore north of Geraldton earlier this week had no visible signs of injury or disease. However, an investigation into the death of the four-metre male shark found it had a large sea lion stuck inside its throat."

It is thought the shark choked to death on the sea lion. Rory McAuley, principal research scientist for the department, told perthnow.com.au: "Such a large object may have damaged the shark's internal organs or impeded water flow into his gills, contributing to his death.

"Alternatively, the shark may have accidentally become stranded in his attempts to get rid of the obstruction."

The shark had been tagged off the coast of South Australia in January. McAuley said the sea lion being stuck in its throat might explain why the shark was swimming so close to shore – unusual behaviour for a great white.

"This could explain why the shark was exhibiting such unusual behaviour in shallow waters off Coronation Beach," he said. "It's possible that the shark was trying to dislodge the blockage."