Two headless New Zealand fur seals were washed up ashore on a South Australian beach on Thursday.
The horrific incident of the decapitated endangered NZ seals prompted a thorough investigation by authorities as New Zealand's penalty for killing a fur seal is two years jail term or a $100,000 fine.
The decapitated animals were found at the Lower Eyre Peninsula. One of the seals was only a juvenile and was badly decomposed. The other seal was in a less decomposed state, a spokeswoman from Natural Resources Eyre Peninsula said.
Occurrences of headless seals being washed up ashore were also happening in some other countries. Such incidents had always baffled authorities and experts.
On June 25, five headless seals were found on the banks of Quebec's Gaspe' Peninsula.
Josiane Cabana, spokeswoman for the Quebec emergency network for sea mammals, said that the cuts that severed the animals' heads from their bodies were accurate. While her organisation is considering several suspicious possibilities, they are more leaning towards humans being the culprit or perhaps a boat propeller.
Experts also considered the return of the great white shark, with it eating the seals, as one possibility.
However, Jeffrey Gallant, a scientist with the Quebec Shark Observatory, said that if it is the great white shark, the whole bodies of the seals might have been fully consumed.
"They're very opportunistic feeders and it would make no sense whatsoever for a shark to eat only the head and not feed upon the entire carcass when they don't get to feed that often, or at least not every day. So to just find the heads missing does not make a lot of sense," Gallant said.
Stéphane Lair, a professor at the university's Faculty of Veterinary Medicine, proposes the theory that scavenger species were the culprits as they usually go for the head first.
"Scavengers attack a carcass quickly, and they go for orifices - the nose, the mouth, the nostrils. So it's the head that comes away from the body first," Lair said.
He explained that the carcasses of these headless seals might have been just washed up on the shore of Gaspe' but it does not mean that the animals were killed there. Scavenger species usually live in more remote locations.
In 2008, when headless seals were discovered in Scottish waters, wild life advocates drew the conclusion that the heads were cut off to conceal evidence that the animals were shot in the heads.
The cutting was done to avoid having the bullets associated to the calibre of the gun used in shooting.
"There must be a strong suspicion that these seals were killed illegally," Advocates' Political Director, Libby Anderson said.