Two members of a fox hunt have been questioned by police on suspicion of illegal hunting, the BBC can reveal.
Video footage from the League Against Cruel Sports allegedly shows members of the Meynell and South Staffordshire Hunt involved in cub hunting - which trains hounds to hunt foxes.
The hunting of wild mammals with dogs is illegal in England, Wales, and Scotland.
The hunt said it was "assisting the police with their enquiries".
Investigators from the League Against Cruel Sports secretly filmed the Meynell and South Staffordshire Hunt in October.
Riders on horseback
The videos, which have been released to the BBC, are said to show hounds being sent into a wood to hunt for foxes while riders on horseback are spaced at even intervals in the open.
So-called "terrier men", who assist the riders, are also present on quad bikes.
At one point a fox is seen on the video running across a field, and it is chased by riders for a few seconds before they turn round.
The video was submitted to Derbyshire Constabulary in October, and last week two members of the hunt were questioned by police officers.
Police say they intend to question more people in January.
In a statement, issued via the Countryside Alliance, the hunt said: "We can confirm that the Meynell and South Staffordshire Hunt are assisting the police with their enquiries following an allegation of illegal hunting but are unable to comment further while the investigation continues."
The video was filmed by League Against Cruel Sports investigator, Roger Swaine.
He also filmed the Meynell and South Staffordshire Hunt cub hunting seven years ago and the footage secured convictions against the hunt master and a hunt employee.
It remains the only successful prosecution for cub hunting since the Hunting Act came into force in England and Wales in 2005.
The League Against Cruel Sports says it has received 138 reports alleging cub hunting, involving 73 hunts, since this summer.
Cub hunting takes place between late summer and the start of November, when the main hunting season begins.
Many hunts say they only engage in trail hunting, in which hounds follow an animal scent trail left by hunt members on foot, horse-back, or from a quad bike.
The Countryside Alliance says that if hounds pick up the scent of a real fox the huntsmen will stop the hounds as soon as they are made aware.
Andrew Bomford's report is for Radio 4's PM programme.