WARNING – GRAPHIC IMAGES: Authorities are appealing for public assistance after a beheaded whale was discovered on a remote beach on the NSW Mid North Coast.

A local resident alerted authorities on Monday after finding the remains of the animal – believed to be a pygmy sperm whale – on Smith’s Beach at Mitchell’s Island.

A National Parks and Wildlife Service (NPWS) spokesperson confirmed the whale had been dead for some time before someone removed its head.

“The carcass was reported to the National Parks and Wildlife Service (NPWS) by a member of the public via the Enviroline,” the spokesperson told Yahoo News Australia.

While the carcass has since been removed, authorities have reiterated that taking the head or any part of a marine mammal is a criminal offence.

“People are reminded that all marine mammals are protected in NSW and it is an offence to remove any part of the animal, even if it is dead.”

Pygmy sperm whales are seldom seen in NSW waters except when stranded. The species is typically solitary, found in temperate and tropical waters offshore and can grow up to 3.8 metres.

MidCoast Council confirmed it was notified of the incident.

“Staff attended the site and noted that the head had been removed,” a council spokesperson said on Wednesday.

“On this basis, and as per marine carcass management protocols, NPWS were notified who attended the site and authorised the removal of the carcass yesterday afternoon [Tuesday].

“The carcass has since been disposed of.”

Authorities are urging anyone with information to contact investigators.

“NPWS is asking for anyone with information about this incident to contact the Environment Line 1300 361 967 or Crimestoppers on 1800 333 000,” the spokesperson said.

Officials have noted that such incidents are not isolated.

Whale bones can be valuable on the black market, although many people take them simply as souvenirs.

Last year, visitors to K’gari (formerly Fraser Island) were warned not to remove bones from a decomposing whale calf after one visitor strapped a bone to the roof of his 4WD.

Queensland authorities warned offenders face penalties of up to $483,900 or two years’ imprisonment.

New Zealand has also experienced repeated whale bone thefts.

In May, the Department of Conservation warned offenders could face fines of NZ$250,000 after a chainsaw was used to remove the jawbone from a 15-metre sperm whale on the South Island.

A similar incident occurred in 2015 when thieves targeted another beached sperm whale.

Images: DESI / Facebook