WARNING: Footage contains graphic images some viewers may find distressing.

An abattoir boss and three workers have pleaded guilty to causing unnecessary suffering to animals after a campaign group recorded horrific abuse taking place at a north Yorkshire slaughterhouse.

Secret footage filmed at the Bowood slaughterhouse captured the workers repeatedly punching, kicking and throwing the animals, as well as killing them before they were stunned.

In one instance, a worker can be seen standing on the neck of a conscious sheep then bouncing up and down. Another worker is filmed holding a sheep by its throat and threatening to punch it.

The footage, released by the Animal Aid campaign group, shows the workers repeatedly hacking away at the necks of sheep in disregard of the rules of halal slaughterhouses.

The footage, filmed over three days in December 2014, led the government to rule that CCTV cameras had to be installed in all slaughterhouses in England. Local authorities have been granted unrestricted access to footage.

William Woodward, 32, the owner of Bowood Farms Ltd, pleaded guilty at Northallerton Magistrates Court to failing to prevent acts by employees that caused the animals to suffer.

Slaughterhouse worker Artur Lewandowski, 33, of Darlington, admitted causing unnecessary suffering to four sheep.

Kabeer Hussain, 44, of Bradford, pleaded guilty to one charge of failing to give 24 sheep sufficient time to lose consciousness before they were slaughtered.

Kazeem Hussain, 53, also from Bradford, admitted one charge of not giving 19 sheep sufficient time to lose consciousness and a further charge of failing to cut the throats of six sheep in the required manner with a single cut.

Not an isolated case

The defendants will be sentenced at Leeds Magistrates Court on 2 March.

Animal Aid director Isobel Hutchinson: "We are heartened to hear that this long-running case, which involved appalling animal abuse, has finally moved towards a conclusion.

"We would urge the public to remember that this is not an isolated case. Over and over again, Animal Aid has filmed lawbreaking inside UK slaughterhouses.

"Whether stun, non-stun or even so-called 'higher-welfare' establishments, we have repeatedly found vulnerable animals being subjected to illegal abuse.

"Even when laws are being followed, which often they are not, there is no such thing as a humane death at the slaughterhouse. These are brutal, bloody and terrifying places."