Video released by Animal Liberation NSW shows pigs at a South Australian piggery being ridden by workers, kicked and purportedly having their ears cut and teeth removed without anaesthetic.
The footage said to be shot at Yelmah Piggery in 2015 and 2016 also shows decomposing carcasses scattered around the site.
The activist group's Campaign Director Emma Hurst told AAP an RSPCA investigation is underway but she believed a prosecution was unlikely as what is shown is considered standard industry practice.
The piggery's owner Tony Richardson said in a Daily Mail interview that his staff were well trained and not cruel, but conceded Yelmah was an old property in need of renovation.
AAP has contacted RSPCA for comment.