Fox hunt supporters are systematically blocking badger setts, leaving the legally protected mammals to slowly suffocate, campaigners said.

Volunteers said they filmed, photographed or noted nearly 150 cases of setts being blocked in and around the Cotswolds in the 2017-18 hunting season, and have sent a dossier to police.

But they believe such illegal activity is commonplace across the British countryside.

Hunt supporters are suspected of blocking setts to prevent foxes “going to ground” – escaping – while being chased by packs of hounds trained to target and savage them.

However, the 1992 Protection of Badgers Act made it an offence to kill a badger or damage, destroy, obstruct or disturb a badger’s home.

Observers say the alleged blocking of setts also offers circumstantial proof of widespread illegal fox hunting.

Since the 2004 Hunting Act was passed, hunts are permitted only to “trail hunt” – using a prelaid fox scent trail for hounds to follow. Badger setts do not need to be blocked for trail hunting.

Hunt monitors from Gloucestershire, Worcestershire, Herefordshire and Cirencester say they recorded 148 instances when the entrances to setts were covered over.

In many cases, they said they saw terriermen openly associated with hunts, unidentified men or masked men carrying out the blocking, either the evening before a hunt meet or on the morning of the hunt.

Terriermen traditionally accompany hunts. According to the League Against Cruel Sports, they normally following riders on quadbikes with terrier dogs in cages, which are used to flush out foxes that have gone underground.

There is no suggestion that representatives from the hunts were themselves involved in the alleged activity.

Photographs show that sometimes sett entrances are covered with just earth, leaves and twigs, but some have been seen blocked with compacted soil, heavy clay, building rubble, rocks, plastic drums, fence posts and other heavy objects that would be impossible for badgers underneath to move. The animals then become trapped and suffocate or starve to death.

Denise Ward, an anti-fox hunting volunteer, told The Independent: “We recorded over 140 blocked setts but we think our recordings could be the tip of the iceberg across Britain. We covered a small minority of hunt days and only covered a limited area, but it does give a clear picture of the incidence of badger sett blocking.

“Trail hunts do not necessitate blocking badger setts so this really exposes the myth that fox hunting no longer goes on.

“It means double cruelty to our native wildlife – to foxes and badgers.

“This strong circumstantial evidence of illegal hunting is not widely known among the public.”

Many of the sett blockings were in the official badger cull zone, increasing the threat to biosecurity, according to campaigners. It is well known that when badger families are disrupted through deaths, others move into the area.

Until hunting was outlawed in 2005, it was legal to temporarily block badger setts with soft soil or straw but the practice is still believed to be widespread across the UK.

Steve Harris, head of enforcement at the League Against Cruel Sports, said badgers would suffocate when entrances are blocked by heavy duty items if there were no other sett exits.

“Tunnels are no wider than a badger and one trying to dig its way out would have nowhere to put the soil. It would need to excavate around itself first,” he said.

“Sett interference is very widespread. It takes up more than half of reported incidents of badger persecution to the National Wildlife Crime Unit.

“Data shows a clear correlation between sett blocking and the hunting season – it peaks in the winter and drops in the summer, taking off again in autumn.”

The Independent asked the hunting group that the campaigners claim had the most evidence against it for comment.

One senior member said: “I have no evidence of what you are talking about. You should speak to the Masters of Foxhounds Association. I have no idea who you are – you could be anyone,” before terminating the call.

Wildlife Photographer of the Year People’s Choice award Show all 8 1 /8 Wildlife Photographer of the Year People’s Choice award Wildlife Photographer of the Year People’s Choice award Winner – Pikin and Appolinaire Pikin, a lowland gorilla, had been captured and was going to be sold for bushmeat but was rescued by Ape Action Africa. Jo-Anne took this photograph as the gorilla was being moved from her former enclosure within a safe forest sanctuary in Cameroon to a new and larger one, along with a group of gorilla companions. She was first sedated, but during the transfer to the new enclosure she awoke. Luckily, she was not only very drowsy, but she was also in the arms of her caretaker, Appolinaire Ndohoudou, and so she remained calm for the duration of the bumpy drive Jo-Anne McArthur Wildlife Photographer of the Year People’s Choice award Finalist – Elegant Mother and Calf Every year from July to late October southern humpback whales migrate north from their Antarctic feeding grounds to give birth in the warm sheltered waters off Tonga. Ray encountered this humpback mother and calf peacefully floating in the plankton-filled water around the island group of Vava’u, Tonga. After Ray gently approached them, the giants swam a bit closer to have a look at him. While they made this elegant turn, Ray took the shot. He later converted the image into black and white which he felt represented the simplicity of the scene Ray Chin/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Finalist – Warm Embrace When polar bear mothers and cubs emerge from their dens in the early spring, the cubs stay close to their mothers for warmth and protection. Once the cubs are strong and confident enough, they make the trek to the sea ice with their mother so that she can resume hunting for seals. Debra waited six days near the den of this family, in Wapusk National Park, Manitoba, Canada, before they finally emerged. In the most challenging conditions she has ever faced, temperatures ranged from -35C to -55C with high winds, making it almost impossible to avoid frostbite and keep her camera gear functioning properly Debra Garside/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Finalist – Roller Rider Lakshitha was on safari in MaasaiMara National Reserve, Kenya, when he spotted an unusual sight – a lilac-breasted roller riding a zebra. Normally they prefer to perch high up in the foliage, but his roller spent an hour or more riding around and enjoying the occasional insect meal. Lakshitha waited for the surrounding zebras to form the perfect background before taking this tight crop Lakshitha Karunarathna/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Finalist – Sloth Hanging Out Luciano had to climb the cecropia tree, in the protected Atlantic rainforest of southern Bahia, Brazil, to take an eye-level shot of this three-toed sloth. Sloths like to feed on the leaves of these trees,and so they are often seen high up in the canopy. Luciano Candisani/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Shortlisted – Reach for the Sky Steven was taking pictures of a small group of adult roseate spoonbills in a rookery in Tampa Bay, Florida, when he noticed a newcomer flying in from afar. With just enough time to back up a few steps, Steven photographed the bird landing exactly square to his camera with its wings in a stunning symmetrical U-shape Steve Blandin/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Shortlisted – Holding On This close-up captures the touching moment an infant lays its small hand in the big hand of its mother. Jami took this photograph while she was in Borneo working on a story about the effects of palm-oil agriculture on orangutan habitat. Loss of primary rainforest is a serious threat to this already critically endangered species Jami Tarris/Wildlife Photographer of the Year Wildlife Photographer of the Year People’s Choice award Shortlisted – Blood Ivory In a protected area of Zululand, KwaZulu-Natal, South Africa, a ranger’s bloody hand rests on a heavily grained ivory tusk, also covered in the blood of an African elephant. The bull had to be destroyed due to a severe tusk infection that couldn’t be treated.The tusks were removed to a place of safekeeping, where they were carefully catalogued in accordance with legislation Peter Chadwick/Wildlife Photographer of the Year

One of the joint honorary secretaries said: “We have a lot of these types of allegations, which are completely unfounded. The police are carrying out enquiries and no response has been made to us.”

A spokesperson for the Masters of Foxhounds Association said: “All of the hunts referred to regarding these allegations are members of the Masters of Foxhounds Association (MFHA). The MFHA promotes hunting within the law and in accordance with the Hunting Act 2004.

"If a member of the public has evidence of offences being committed in relation to our membership, they should inform the police, who will conduct a proper investigation if they think there is sufficient evidence to do so.

“As an association, we are aware that allegations are regularly made or suggested online by anti-hunt groups and activists. They are generally without justification.

“If any of these allegations are investigated by the appropriate authorities, we anticipate that the hunts will deal with them. Certainly it would not be appropriate for them or us to respond to allegations through the medium of a news story.”