Footage recorded on National Trust-managed land allegedly shows the hunters preparing for a deer hunt across the Holnicote Estate on Exmoor.
The video reputedly shows riders gathered on National Trust land, with hunt supporters looking at the scene from nearby cars reportedly parked illegally on the moorland.
A herd of deer can also be seen running across the land as onlookers observe from the nearby road.
Andrew Kendall, a professional investigator for the League Against Cruel Sports (LACS) who witnessed the incident, said: "Deers were clearly being flushed out of wooded valleys and chased onto open moorland on the hottest day of the year which is clearly detrimental to their health.
GETTY•YOUTUBEAnimal Cruelty: Footage allegedly shows hunters preparing to give chase to a deer pack
“We’re in the middle of the young stag hunting season. Sadly a young male deer would have been chased for miles by hounds pursued by horsemen and women and followers on quad bikes, before being shot.”
The shocking video was recorded one day before National Trust