Push to free 'Olivia' the pig after claims of Midland Bacon farm worker's hideous 'pants dropping'...

The son of a piggery manager is preparing to face court on bestiality charges after allegedly sexually assaulting a female pig, as activists demand the animal is released.

Bradley O'Reilly, 30, was charged after allegedly being caught on a secret camera by activists inside Midland Bacon pig farm, where his dad Ricky O'Reilly is a boss.

The video shows a person with their pants down allegedly raping Sow No. 8416, now given the name Olivia by activists, on February 11.

Victorian detectives charged Mr O'Reilly after being handed the video footage by activists from Farm Transparency Project (FTP) who allegedly broke into Midland Bacon in Carag Carag, north central Victoria, to plant the camera. 

The FTP has now set up a Change.org petition demanding the sow's release and the campaign for Olivia is being supported on Instagram posts and video posts.

Activists have also staged a protest outside the piggery gates with placards and fluffy pig toys.

Prominent animal rights campaigner, Sophie Wilcher, who started the petition for Olivia, claims the footage shows Mr O'Reilly assaulted the pig in a restrictive pen after the end of a work shift.

The video allegedly shows him drop his trousers and commit the alleged sexual assault.

Sow No. 8416 was at the time in a farrowing crate, which deliberately confine sows during pregnancy and after birth to reduce the risk of the mother lying on and crushing its newborn piglets.

'We have made this footage available on our website, alongside other photos and footage of standard, routine cruelty at the same facility,' FTP said.

The camera that activists planted inside the piggery was not intended to expose any bestiality, but other alleged incidents of maltreatment that the FTP was investigating.

This allegedly included piglets being killed with blunt force, and procedures carried out by farm hands with no anaesthetic such as removing teeth, which is legal animal practice. 

The O'Reilly family is well known in the community - father Ricky is a life member of the Stanhope Football Club, while the accused Brad won the club's 2019 award for 'most determined' and played there alongside his brothers.

Ricky O'Reilly, who has been manager of the piggery for 13 years, would often deliver Christmas hams to the local community, the Herald Sun reported, and feared the activists breaking in, saying it had caused him sleepless nights.

The petition to 'help save out Olivia 'has reached 26,300 of 35,000 signatures and has been tabled in NSW Parliament, and may also be in Victoria's parliament.

The petition said: 'Please sign this petition to urge Midland Bacon to release sow 8416 into the care of Peanuts Well-being Sanctuary immediately.

'Allowing her to live out the remainder of her days in peace, and safety, is the absolute minimum they can do.'

Sophie Wilcher told Daily Mail Australia that Olivia may have been moved to another piggery owned by the same company, and want assurances she is being looked after.

'We've been told she is being taken care of, but she's had no medical attention and the RSPCA say they only deal with physical care and don't account for emotional or mental wellbeing,' she said.

She had posted flyers to 1700 residents in Carag Carag asking 'have you seen this sow' and offered a $500 reward.

Brad O'Reilly will face Echuca Local Court in June on one charge of bestiality.