The group are thought to be behind the slaughter of a sheep found dead on farmland after it had been mauled by a dog.

They gather in isolated fields, spreading out to track down hares which are then chased and killed by their dogs.

Police have received more than 30 reports of unlicensed hunters being spotted in the area since September when the fields were cleared of crops.

Unlicensed hunters

PC George Lager, a rural beat officer from Gloucestershire Police, said: "Illegal coursing always ends in the death of the hare - participants continue until there are no animals left to kill.

"There is little control placed on the dogs and they can indiscriminately attack any livestock close by."

PC Lager appealed for people to help track down the hunters, who are well-organised and difficult to catch.

He said: "Mobile phones mean the offenders can gather at short notice in fields hidden down country lanes.

"We need farmers and members of the public to be our eyes and ears and call us if they spot anything.

"We want people to video any suspicious activities rather than confronting people so they are less at risk."

Anyone caught hare coursing can be fined £200 and have their dogs and vehicles confiscated.