Children as young as seven have been pictured using dogs to hunt and kill foxes in Northern Ireland.
Shocking images have been released by campaigners who are calling for underground hunting to be banned. One of the images shows a child holding a dead fox in one hand and a gun in the other.
The League Against Cruel Sports say enthusiasts involved in 'terrier work' - the practice of sending small dogs below ground to flush out foxes - are increasingly turning to social media to boast about their exploits.
The group says that the practice is legal across the UK. It is exempted from the Hunting Act (2004) in England as long as the person carries written permission and intends to shoot the fox humanely as soon as possible after it is flushed out.
However, the League, which is calling for a ban on terrier work, says the practice often leads to fights and terrible injuries to both animals. Foxes are sometimes caged and taken away so that fighting dogs can be unleashed on them.
Northern Ireland spokeswoman, Janice Watt, branded the practice "shameless, legalised cruelty" and said she has seen numerous distressing images on social media that make it clear that the animals have undergone terrible suffering before their deaths.
Among the gruesome images she has gathered from the Facebook pages of men and women bragging about their exploits in Northern Ireland were a pregnant rabbit whose embryos had been torn out of her body, foxes placed in a cage so that fighting dogs could be let loose on them and dogs which had suffered horrific facial injuries after fighting with foxes.
"There's almost like a one-upmanship on social media. The more gruesome it is, the more they show off what they've done and the happier and prouder they are," she said.
"This is going on every day and night somewhere near you in a field. It comes under terms like offering a service for pest control. But one thing that is apparent from all the studies we've done is that the person that carries it out gets a thrill from seeing an animal torn apart."
Among the images were two of boys posing with prey animals. One young boy is seen holding a dead fox and posing with what appears to be an air rifle - it is understood that in Northern Ireland it would be illegal for him even to be holding this weapon as the law stands.
Ms Watt said she has seen images of children as young as seven or eight taking part in hunting with dogs, including some young girls.
Indeed, one of the enthusiasts who got into a heated argument on Facebook defending the practice turned out to be an eight-year-old boy.
"A lot of these children are being taken along to help out. It's not uncommon for there to be a few wee boys going along to learn the ropes as well," Ms Watt said.
"They cannot fail to be affected in a negative way. This is teaching them to disregard the welfare of the chosen prey animals. The fact that you're teaching children that it's okay to inflict that violence on a living being is the most disturbing thing about it.
"We are supposed to be instilling good morals and ethics in children. To take them out to witness that kind of barbaric cruelty and teach them to think it's okay to encourage a dog to attack and kill a wild animal is very worrying."
Ms Watt said terrier work is regarded as the very low end of pest control and is a "loophole" with a big overlap with criminal offences such as badger baiting and dog fighting.
"They often haven't asked permission to go onto people's land and this is a real nuisance across the countryside," she said.
Some dogs die of suffocation underground and others are left with horrific injuries after fighting with their prey, such as one Springer spaniel that was put down by a vet in Northern Ireland earlier this year after its nose was torn off.
The League is calling for a complete ban on hunting in Northern Ireland as part of its NI Charter, which has been backed by Mid Antrim Animal Sanctuary, Lucy's Trust and the International Fund for Animals.
Minister of the Environment Mark H Durkan said: "I am concerned with preventing acts which are deemed to be cruel to wild animals.
"Legislation to ban hunting with dogs in Northern Ireland is a matter for the Executive to consider. It is unlikely that this could be achieved within this mandate of the Assembly given the limited time it has left."