A freshwater crocodile, skinned from its head to tail, was found in the Murray River near Barham on Sunday.
Gold Coast electrician Brent Lodge found the reptile while out fishing and recorded a video that he posted to Instagram.
As of July 23 the post has attracted over 3000 likes and 1800 comments.
Mr Lodge told Fairfax that he found the 1.8-metre-long crocodile floating belly-up amongst litter in the water.
"I just thought it was a big Murray cod or a dead goanna. But when I got closer I realised it was a crocodile.
"It was six-foot-long, a bit taller than me, and there was a hook going through its mouth.
"Everyone thinks it's a hoax but I'm not joking around. That's why I took a video because I knew nobody would believe me.”
Mr Lodge said he contacted the New South Wales Department of Primary Industries before the police.
When contacted yesterday for comment, they said reptiles were not in their jurisdiction.
Freshwater and salt water crocodiles are protected species under Australian law.
The illegal taking of a crocodile could warrant a penalty of more than $28,000 in some states.