The world's largest captive crocodile has died.

Cassius, who lived at Marineland Melanesia Crocodile Habitat, on Green Island near Carins in Far North Queensland was almost 5.5m long.
The saltwater crocodile is thought to have been over 110 years old.

Cassius held the Guinness World Records title as the world's largest crocodile in captivity.

"He was more than just a Crocodile he was a cherished member of our family and brought joy and companionship to his best mate George for over 37 years," the park said on Facebook.
They added that his health went downhill after George was moved.

"George had only recently relocated into Cairns from Marineland after 52 years living on Green Island to an assisted care residence on the 5th October," the post said.
"Cassius's condition declined since the 15th of October.

"He was very old and believed to be living beyond the years of a wild Croc.

"Cassius will be deeply missed, but our love and memories of him will remain in our hearts forever."

Cassius had lived at the park since 1987 when he was relocated from the Northern Territory.

Visitors were able to watch him being hand-fed.

The park is home to more than 15 crocs. (Courtesy 9 News)