Disturbing new video has emerged of sheep in New South Wales, South Australia and Victoria being stomped on the head, brutally cut and bashed with hammers.

Filmed by undercover investigators the video has sparked calls for a total boycott of all wool products.

Released by animal rights organisation People for the Ethical Treatment of Animals (PETA), the hidden camera footage shows Australian shearers beating, cutting and mutilating sheep as they sheared the animals.

One worker can be seen hitting the sheep’s head with a hammer. Several sheep were left bleeding and unattended for several hours or overnight, PETA also reported.

The undercover footage was initially provided to US-based network NBC News, but is now available online.

Please note, some readers may find this video disturbing:

"PETA's in-depth investigations show that—no matter how much anyone might wish it to be so - there is no such thing as 'humane' wool," said Daphna Nachminovitch, an official at PETA.

"The industry is infested with violence and PETA documented cruelty in nearly every shearing shed that we entered."

PETA say they sent three undercover investigators to 19 different shearing sheds across Victoria, New South Wales and South Australia between late 2012 and March 2014.

According to NBC News, Australia is the source of about 20 per cent of the world’s wool, including 80 per cent of the merino wool.

"PETA estimates that the shearing contractors it investigated may account for more than 5 per cent of Australia’s annual output," the network reported.

The RSPCA has launched an investigation into the "serious" allegations for potential breaches of state animal welfare laws.

"Shearing is stressful for sheep and it should be carried out by trained and competent workers," a spokeswoman said in a statement.

WoolProducers Australia has condemned the "unacceptable" behaviour of workers captured in the video, but says it is an isolated incident.

"We are shocked and appalled by the footage," WoolProducers Australia's president Geoff Fisken said in a statement to AAP.

"We ask all woolgrowers to take a zero tolerance approach to poor animal welfare practice and take the necessary steps to ensure rare behaviour like this ends."

Mr Fisken said the industry has invested in research and training to improve animal welfare.

The Department of Agriculture said it had full confidence the matter would be investigated appropriately by the RSPCA and state authorities.

But it’s not just an Australian problem. In another PETA video, US shearers can also be seen slamming sheep on the floor, kicking and stomping on their heads.

PETA has called on the public to sign a petition and to boycott all wool products in favour of cruelty-free material and fabrics.

Please note, some readers may find this video disturbing:

- with AAP