A devil tattoo on a severed arm among body parts found floating in a Melbourne river is the first hope of identifying the victim, police say.
Two severed limbs and a bag of flesh discovered in Maribyrnong River on Thursday are believed to have been there for up to a week.
Detective Inspector Michael Hughes says publicly releasing an image of the red devil tattoo is unusual but he hopes it will provide an early breakthrough.
"I feel for the family ... they're going to find out by seeing it on the media but I think it will shorten our investigative time," he told reporters on Friday.
Police divers stopped work on Friday night after searching the river all day for more evidence.
The forearm, severed at the elbow and wrist, was found floating near The Boathouse restaurant at Moonee Ponds.
Another limb and the black plastic bag of human flesh were retrieved upstream.
Police believe the man's killer possibly removed his hand to dispose of identifying fingerprints, and see the tattoo as their best alternative.
"It looks like a devil. It's got an unusual piece around the face which we can't really identify," Det Insp Hughes said.
"He's holding a pitchfork in his right hand, a three pronged pitchfork. In his left hand, it appears to be a spray can. It could be a fire extinguisher."
The body parts had likely been in the river for a week at most, he said.
Police don't yet know how the body was dismembered but believe it happened elsewhere and the river was simply used as a dump site.
"They are major limbs," Det Insp Hughes said.
Detectives searched the river by boat on Friday morning, and divers focused on a bridge about two kilometres from the restaurant.
