"Cassius" has reclaimed his crown as the world's biggest crocodile in captivity after his rival for the title died, with the huge reptile's handler in Australia saying Tuesday it will boost business.

The 5.48-metre (17 ft 11ins) crocodile, kept in a park on an island off Australia's Queensland, held the record until "Lolong", a 6.17-metre suspected man-eater, was caught in the Philippines 17 months ago.

But with Lolong's death from a mystery illness on Sunday, Cassius is once again on top.

"The Guinness Book of World Records contacted us as soon as Lolong died," Billy Craig, a croc wrangler at Marineland Melanesia where Cassius lives, told AFP.

"They said the record will revert back to us. It's definitely good for business.

"We changed the sign to the largest crocodile in captivity in Australia, so I guess we can now just remove the Australia part and put it back to the whole world," he added.

A government-sanctioned hunting party caught Lolong, believed to be around 50 years old, near the town of Bunawan in the country's remote south in September 2011 after it was suspected of biting the head off a young schoolgirl and of eating a fisherman.

Its capture made the town famous and Lolong, named after a local crocodile hunter, became a big tourist attraction.

Cassius, estimated to be 110 years old, has been in captivity for 26 years, having been caught in a Northern Territory river after attacking boats and biting off outboard motors.

He was sold to George Craig, who trucked him 3,000 kilometres (1,860 miles) to Green Island on the Great Barrier Reef where he founded Marineland Melanesia.

Billy Craig said it was a pity Lolong died so young, with a potential 50 years of growth ahead.

"It's a real shame. Imagine what size it could have grown to in another 50 years," he said.