Animal rights organisation PETA hopes an official investigation into alleged animal abuse on sheep farms will result in criminal convictions.

The Ministry for Primary Industries has finished the first phase of its investigation into animal welfare breaches connected to shearing practices, triggered by undercover video footage shot by People for the Ethical Treatment of Animals on 11 farms.

The videos showed workers standing on a sheep's neck, dragging sheep across the floor, and sewing up a bloody wound without painkillers.

The ministry said the "very concerning" acts identified in more than 200 video files were the focus in the next phase of the investigation.

PETA Asia-Pacific said the farms at the centre of the allegations supplied ZQ-certified wool - which claimed to be the "world's leading ethical wool brand".

Its campaign manager Abigail Forsyth said she was pleased MPI was taking quick action, but she was not confident those responsible would be held accountable.

"History shows us that cases of animal abuse ... typically go unpunished, whether that's due to weak animal protection laws, or political agendas, or a reluctance to challenge powerful industries," she

said.

PETA was also urging the New Zealand Merino Company - which owns the ZQ standard - to install cameras in ZQ farms' shearing sheds.

The company said it had suspended two ZQ farms following its own investigation into breaches of its standards.

"Through the publicly available footage NZM has been able to identify two ZQ farms, along with a number of non-ZQ growers," chair Kate Mitchell said.

"NZM immediately suspended these farms from the ZQ programme and will move to determine if any breach of the ZQ Standard has occurred. If further information or footage is released we are

committed to expanding our investigation."

NZM was appalled by the footage and "unequivocally condemn" the mistreatment of animals, Mitchell said.

NZM had also quarantined unprocessed wool from the two farms, begun a rapid assessment of all ZQ farms to ensure protocols are being met, and ramped up spot inspections, she said.

The company was also considering the use of video surveillance and the presence of animal welfare officers during shearing.

Merino company says it will probe sheep cruelty claims