Disturbing footage had been released following a campaign group's investigation into two pig farms.

Viva! Campaigns, a UK vegan campaigning group made the video public after investigations took place over the course of three weeks, using hidden cameras to reveal the atrocities taking place inside the farms’ sheds.

The farms in question, Calvesley in Yattendon and Whiteshoot in Oxfordshire are owned Winterbrook Farm Partners and supply British supermarket giant, Morrisons.

Both farms are approved by the consumer assurance scheme Red Tractor, which claims all of their farmers’ ‘animals have been well cared for’'.

Hidden footage - which the Gazette has chosen not to include but can be seen on the Viva website here - captured at these farms reveals a catalogue of disturbing scenes.

At Whiteshoot Farm, investigators discovered a piglet with an enormous growth on its stomach, dumped in a gangway and writhing in pain.

The team stumbled upon an entire shed of sick animals – victims of bullying, cannibalism and common pig farm ailments like prolapses.

Animals contained in the segregated pens were covered in lacerations and grotesque bites, injuries inflicted on them by other pigs who are "driven to insanity by the barren environment."

Calvesley Farm revealed much more.

One of the scenes captured by Viva! Campaigns shows a farm worker ‘knocking’ young piglets – killing them by slamming their tiny heads onto the concrete floor. An act which is followed by the worker dumping the bodies aside.

This breeding unit is home to hundreds of female pigs who are routinely impregnated and forced to birth countless litters of piglets. This farm produces on average 400 piglets a week.

Hidden cameras reveal workers on-site carrying out routine mutilations. Each newborn piglet is pulled from its stall and thrown into a metal trough. Investigators captured workers using a hot knife to slice the piglets’ tails back to a bleeding stump and a pair of pliers to clip away their teeth – all without pain relief. These cruel acts are supposed to prevent tail biting, a behaviour that manifests from distress and lack of stimulation.

Since launching the investigation a spokesperson for Red Tractor, said: ''We were very disappointed by some of the images in the footage.

''Protecting animal health and welfare is one of our top priorities. Red Tractor requires all members to meet every standard, every day and take any allegations of breaches seriously.

"We immediately launched an investigation and as a result the farms' Red Tractor Certification have been suspended and sanctions put in place to address the issues raised through this process."

Viva!’s founder and director Juliet Gellatley explains her concerns about factory farming:

“Our team witnessed appalling conditions in this investigation, documenting the systematic abuse of farmed pigs, whose short lives are filled with nothing but misery and pain. While some pigs were ruthlessly mutilated with barbaric hot knives and pliers, others were left to die slow, agonising deaths from their injuries – all for the sake of food.

"This investigation reiterates the fact that supermarket welfare claims and regulatory bodies such as Red Tractor are nothing but a façade for the horrendous, brutal and cruel reality of intensive factory farming in this country.

"These are not aberrant farms – they are typical of what is permitted by government and retailers. I think the customers of Morrisons will be disgusted to see the conditions on these farms.

"Not only do factory farms raise serious welfare concerns, they also create an ideal environment for mutating viruses and antibiotic-resistant superbugs. In fact, most governments thought the next pandemic would be caused by an avian influenza (bird flu) virus emerging from poultry or pigs.

"Our relationship with animals can no longer be just focussed on exploitation, the way meat is produced is now considered to be a global threat. It’s not just a case of banning wet markets, although that can’t come soon enough. We need to stop factory farming too and are calling on consumers to choose vegan.”