The remains of animal carcasses has become a familiar sight in the Tutaekuri River, with many locals outraged at the dumping.
Fly fisherman Mark Elstone said his dogs were constantly finding fresh parts of calves, pigs, cow, sheep and venison and believes it has become a problem.
He believed it was the by-product of a "home-kill situation".
"I doubt very much that a commercial entity would do this and the amount of stuff that is there indicates it is somebody who is doing it after they have been hunting and it is just their way of getting rid of it," Mr Elstone said.
There were three public access points that these parts are being dumped in just before the confluence with the Mangaone River, Mr Elstone said.
Hawke's Bay Regional Council engineering officer Vincent Byrne said during the 16 years he had worked for the council, it had always been a problem.
"I have inquired at the Hastings Transfer station and they inform me they don't take offal which then begs the question, how do you dispose of offal and carcasses," Mr Byrne said.
"We do know from ear tags that a percentage (unknown) is rustled stock. Wouldn't I like to know who was responsible? In my time I have never caught anyone disposing of animal parts."
Although, it appears that it is not just isolated at the Tutaekuri River, with three deer and two pigs found some years ago in the Esk River.
"One of the stags had a good head which I identified through Facebook back to a person.
Despite a police investigation it was deemed insufficient evidence to take a prosecution."
He noted that when the council was notified, it dealt with the removal in popular waterways but said sometimes this was impractical if the animal parts were in deep water or a swamp and machinery was unable to reach the material.
"Sometimes they are so decayed it is not worth removing them."
Hawkes Bay Fish & Game regional manager Mark Venman said: "The dumping of animal body parts or in fact any waste into our rivers, lakes and streams is not acceptable and efforts must be made to apprehend those individuals who are polluting our waterways.
"The rivers are a popular location at this time of year for recreational activities such as swimming, kayaking and trout fishing but no one wants to share the river with large decomposing animal carcasses."
Hawke's Bay Regional Council resource use manager Wayne Wright said there was no specific legislation that applied to animal parts and offal.
"Disposal - it is up to local landfill operators whether or not they accept it," Mr Wright said. "There are a number of companies such as HB Protein whose business is disposal of this kind of thing."
Depending on the circumstances of disposal, it may come under the following acts.
If it is not disposed of in one of the ways listed below, there are no restrictions for members of the public.
1. Discarded as rubbish in a public place - the Litter Act - enforced by police and local councils (not regional councils).
2. Discarded in a manner where it could contaminate water - the RMA - enforced by regional councils.
3. Where it becomes a health hazard - the Health Act - administered by the local DHB or health department.