Hidden-camera video shot during an undercover investigation of sheep shearing in Australia and the U.S. has revealed what the animal rights organization PETA says is evidence of widespread animal abuse, including kicking, stomping, and gaping wounds to skin, ears and penises inflicted by clippers.

“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, a top official at PETA, who added that her group is asking consumers not to wear clothes made of the fabric. “The industry is infested with violence and PETA documented cruelty in nearly every shearing shed that we entered.”

People for the Ethical Treatment of Animals also said that it believed specific U.S. companies had probably purchased wool produced by the ranches visited by investigators in Australia and the U.S, but NBC News was not able to establish that any of the named companies had bought wool sourced directly from those ranches.

In Australia, PETA sent three undercover investigators to 19 different sheep shearing sheds run by nine different contractors in three states between late 2012 and March 2014, and shot video between October 2013 and February 2014. Australia is the source of about 20 percent of the world’s wool, including 80 percent of the merino wool. PETA estimates that the shearing contractors it investigated may account for more than 5 percent of Australia’s annual output.

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PETA charges that in Australia, workers for seven contractors kicked, stomped or stood on animals’ heads necks and hind limbs, while workers for eight contractors punched or struck sheep with clippers. One worker allegedly beat a lamb over the head with a hammer. Workers for five contractors allegedly threw sheep and or slammed their heads and bodies against floors.

When shearing created flesh wounds, PETA says workers did not administer painkillers before using needles and thread to close the cuts.

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A five-minute edited video compilation provided to NBC News by PETA shows alleged incidents of abuse at six of the Australian ranches.

A representative of a non-profit trade group owned by more than 27,000 Australian woolgrowers, defended the standard of care at Australian sheep ranches.

“Australian wool growers genuinely care for health and welfare of their animals so such alleged behavior is very concerning,” said Michelle Lee of Australian Wool Innovation. "AWI categorically and unequivocally condemns the mistreatment of animals. AWI has invested $2.8 million in the training of shearers and wool handlers, training in excess of 4,500 in the past twelve months.”

In the U.S., which produces a tiny percentage of the world’s wool and is a net importer of wool, a PETA investigator worked undercover for a sheep shearing company for seven weeks between mid-March and mid-May 2014.

The investigator went to 25 ranches in Wyoming, Colorado, Utah and Nebraska while working for the shearing company and alleged that he witnessed animal cruelty by three shearers for the company and two ranchers at 14 of the ranches where the company worked.

PETA has asked local authorities in two Colorado counties to file criminal charges against a specific shearer because of alleged acts of abuse witnessed at two ranches. The investigator said he saw the shearer bending and twisting the necks of sheep, stomping on their necks and limbs and poking his fingers into their eyes at the Zahniser ranch in Montrose County, Colorado and a ranch in Moffat County, Colorado.

He also alleged that at the Zahniser ranch the shearer cut a three to four-inch strip of skin off of a sheep’s ear without offering any pain relief. At the Moffat County ranch, the investigator says he witnessed the same shearer allegedly twisting a sheep’s neck so severely that the animal may have died. A voice can be heard on the videotape saying, “I might have killed it.”

A five-minute edited video compilation shot at U.S. locations and provided to NBC News by PETA shows alleged incidents of abuse at 8 ranches, including what PETA says is an ill ram that was left to die overnight on a trailer, and additional instances of sheep suffering large wounds from being sheared.

Messages left at the Zahniser and Moffat County ranches were not returned, and the shearing company did not immediately respond to a request for comment.

Without viewing the PETA video shot in the U.S., a representative of the main U.S. wool industry trade group, the American Wool Council, said that the behavior described by PETA was “unacceptable.”

“We do not condone or support the actions of anyone that results in the abuse of sheep either intentionally or unintentionally,” said Rita Samuelson. “Rough handling of animals that might result in the injury of a sheep is an unacceptable maneuver during the shearing process or anytime when sheep are handled. … Kicking, throwing and poking the eyes of sheep are also unacceptable practices.”

The American Wool Council’s parent group, the American Sheep Institute, has published a guide to animal care for sheep producers and their employees that is available on its website.

PETA forwarded the video and written complaints to authorities in Montrose and Moffat counties in Colorado. Lt. Gary Jackson of the Montrose County Sheriff’s Office said he had prepared a report and sent it to the county district attorney for review. “I saw nothing in the video that is outside the norm for that industry,” said Lt. Jackson. The district attorney did not immediately respond to a request for comment.

But Moffat County Sheriff Tim Jantz said that the content of the video “is highly concerning and we are taking it very seriously. We immediately launched an investigation and that investigation is ongoing. If our investigation shows it is warranted, we will file any appropriate criminal charges.”