A pig farm in Banteay Meanchey province has drawn the ire of the world’s largest animal rights non-profit after videos of its abnormally muscular pigs went viral.

The so-called “double-muscled” pigs, bred in Mongkol Borei district’s Russey Krork commune, have alternately fascinated and disgusted social media users with their rippling muscles and enormous hind legs. People for the Ethical Treatment of Animals (PETA) called the pictures and videos – one of which has 26 million views – “disturbing”.

“Nothing good ever comes when people manipulate animals and their genetic make-up,” PETA Asia representative Marcel Tjandraatmadja said yesterday, adding that the organisation suspects the farm is injecting the pigs with hormones.

Double-muscled pigs are leaner and meatier than a typical pig but tend to have a variety of health issues, according to experts. In 2015, researchers from Seoul National University in South Korea and Yanbian University in China used a gene editing tool to create 32 double-muscled pigs. Many had birthing difficulties and died prematurely.

Farm owner Ky Laysun, 51, denied that the pigs had been given hormones, and said they did not have any health problems due to their enhanced musculature. “Their health problems come from the hot weather, which causes difficulty breathing,” Laysun said.

According to Laysun, his family learned how to breed the massive pigs “by accident”, and have gotten the science down to just two to three generations. He said he sold all 30 females and still has 10 males for breeding and sperm production.