Footage has been passed to the BBC which appears to show fox cubs being put into the kennels of hunting hounds allegedly to train the dogs to kill.
The video, filmed at the South Herefordshire Hunt kennels, then shows apparently lifeless bodies of two fox cubs being removed and dumped in a bin.
Police are investigating the footage and the animals' bodies. Two men and a woman were arrested earlier in June.
South Herefordshire Hunt has suspended a paid huntsman but refused to comment.
The Masters of Foxhounds Association said an independent inquiry, led by former Court of Appeal judge Sir John Chadwick, would take place into "conduct which suggests breaches of the association's rules".
The South Herefordshire Hunt's kennels, situated at its headquarters, have been closed.
Barking and whooping
The video, taken with hidden cameras positioned outside the kennels, show four live fox cubs kept in a cage.
The Hunt Investigation Team, which campaigns against fox hunting, secretly filmed two of the foxes alive inside the cage at night.
Later the cameras picked up a man removing them using a noose and taking two of them, one at a time, into the kennels nearby. Seconds later, the hounds inside can be heard barking.
A whooping noise, which sounds as though it is being made by a human, can also be heard. The Hunt Investigation Team claims this was to "call the hounds on" to attack the foxes.
On each occasion, the man emerges with a fox's apparently lifeless body and puts it in a bin.
Later footage shows the bins being taken away. However, before then, the activists had retrieved two fox cubs' bodies from the bins.
'Gruesome training secrets'
One of the investigation team, who asked to remain anonymous for her safety, said: "When our investigators took those fox cubs out, one of them was disembowelled, one of them had multiple bite wounds.
"Our feeling is that they were fed live to the hounds."
The animals' bodies have been passed to the police.
The Hunt Investigation Team and the League Against Cruel Sports said they were increasingly concerned about activities allegedly used to support illegal hunting.
They say fox hounds are still being taught to kill young foxes through a practice known as "cubbing".
Since the hunting ban, they are less likely to encounter foxes and it is claimed some hunts have a problem with their hounds attacking animals other than foxes.
The ban on hunting with hounds, introduced in 2005, made it illegal to intentionally pursue foxes with a pack of dogs.
However unintentional kills are not banned. It is claimed some hunts deliberately engineer situations where foxes are killed.
Chief executive of the League Against Cruel Sports, Eduardo Goncalves, said: "The hounds won't naturally kill foxes so they must be taught to do so and this footage exposes the gruesome training secrets of hunts in the UK."
'No place in hunting'
The campaigners also say so-called bagged foxes are encouraged to breed in areas where there is no hunting, and then deposited close to the hunt so they can be pursued.
The BBC was shown a so-called artificial earth in another part of the country where the League Against Cruel Sports claimed piping and paving slabs had been used to create tunnels for foxes.
A saucepan nearby appeared to provide a source of water to drink.
Mr Goncalves said such constructions "blew away the myth that fox hunting has got anything to do with controlling the fox population - this is a cruel sport, pure and simple".
However, the Countryside Alliance said that historically gamekeepers routinely encouraged foxes to breed in specific areas so that their numbers could be more easily controlled.
In relation to the Herefordshire footage, Countryside Alliance chief executive Tim Bonner said if the allegations were proven, the activities shown had "absolutely no place in hunting".
Those arrested are on bail while police investigate alleged unnecessary cruelty to an animal. The BBC understands one is a paid huntsman.
The footage does not include evidence the South Herefordshire hunt is involved in illegal hunting, as defined under the 2004 Hunting Act.