UPDATE FRIDAY 1.30PM: Wildlife rescuers believe foxes were responsible for the decapitation of kangaroos in Longlea.
Police launched an investigation calling for any witnesses or information about the killings that were reported last Saturday.
Bendigo wildlife rescuer Neil Morgan said the evidence pointed to the work of foxes.
"I am 100 per cent sure it was foxes," he said.
"I believe the kangaroos were hit by a car and then moved to the side of the road. The foxes have then gone in and taken their heads clean off. It's what foxes do."
Mr Morgan said he had seen hundreds of examples of similar situations where foxes had taken the heads off kangaroos.
He said it was often done with clean precision.
"The same thing happened in Castlemaine last year. They thought it was people doing it.
"The head is taken off so clean you’d think it’s an axe or a very sharp knife... It's pretty gruesome."
"There’s been quite a few left on the side of the road and the head was completely gone, nothing else touched whatsoever."
Mr Morgan said he was unsure why foxes removed the heads off kangaroos but he said it was possibly due to them targeting the smallest part of their bodies.
He said he was relieved to know that it wasn't humans committing acts of animal cruelty.
"It's nice to know we don’t have people out there doing that sort of stuff."
THURSDAY 9PM: AXEDALE Police are calling for public information after three kangaroos were killed and decapitated in Longlea.
Two adult kangaroos and a joey were found with their heads removed at Hawkins Lane about 4.15pm on Saturday.
First Constable Tayler Masson said a woman phoned police after making the grim discovery.
"All three kangaroos were kind of in a line laid out along the grass," he said.
All of them had been decapitated. It was pretty disgusting."
It's believed the kangaroos were killed between Thursday and Saturday and left by the side of the road in between two properties.
First Constable Masson said the culprits could face up to two years in prison or a fine of more than $140,000 for charges of aggravated cruelty to an animal.
He said he was hoping those responsible or any witnesses may come forward with information.
Wildlife rescuers voiced concerns about the nature of the deaths and called for the anyone involved to hand themselves in.
Founder of central Victoria's Wildlife Rescue and Information Network Brenda Cheers said she was disturbed by the fact someone would do that to kangaroos.
"It's a sick method of killing them," she said.
"I feel ill just thinking about it. I don’t know why people do it. There’s just no reason for it."
Mrs Cheers said she hoped there would be sufficient penalties for those responsible.
"The frustrating thing we find is that people are often prosecuted and then let off or the charges are dropped," she said.
"The penalties need to be carried through so that sadistic people that think about doing that think twice."
First Constable Masson said police were keen to speak to anyone who knows anything about the incident or witnessed any suspicious activity in the area.
Police are being joined by the RSPCA in the investigation.
Anyone with information can contact Axedale Police Station on 54397202.