A wild boar expert has warned of "mayhem" as hunters attempt to round up 60 escaped animals in Devon.
About 100 boar were freed from a farm near the village of West Anstey last month, but about 40 have been caught.
Allan Dedames, who owns the Woodland Wild Boar Farm, has called in the local hunt to round the animals up.
But Dr Martin Goulding, a former Department of Environment, Food and Rural Affairs (Defra) scientist, warned that the animals could fight back.
He told BBC Radio Four's Farming Today: "It's potentially very worrying.
"A wild boar will not cause any trouble unless it is bothered and if you go chasing it with dogs or people on quad bikes, you are annoying it.
"If you corner it, it will turn round and attack you. It will certainly attack the dogs and the hunting dogs in this country are not trained to hold a pig at bay.
"There is a possibility that the dogs are fighting with the pigs and the pigs are fighting with the dogs and there will be mayhem."
About 100 people, including the Dulverton Farmers' Hunt, are using dogs and quad bikes to round-up the remaining animals at one end of a valley, and herd them back to their pens.
Hunters were asked to leave guns behind as they began the chase
Huntsman Anthony Allibone said: "The idea is to flush the boar out of the cover.
"Although there have been sightings in the last day or so, we might not even see one.
"We will try and trundle them back towards where they came from if possible, a distance of about a mile.
"It has never been tried before - but this is the last option before shooting them," he said.
Wild boar were hunted to extinction in Britain some 300 years ago
Small breeding population has emerged in East Sussex in last 10 years
Males can weigh up to 200kg
Boar can travel at speeds of up to 40mph
Can reach 25 years of age in captivity
Exceptional hearing and sense of smell, poor eyesight
Males grow upper and lower tusks
Very wary and shy from human contact
The Animal Liberation Front said it was responsible for freeing the animals.
Mr Dedames called in the hunters after complaints from local people that they were scared of going outdoors and from farmers who said they were destroying crops and disrupting livestock.
Two animals have been spotted 40 miles away near Plymouth after making the journey across Dartmoor.
Hunt chairman Dennis Woollacombe, said the operation was a "goodwill gesture" to help get the animals off local farmland.
Before everyone set off he told the assembled crowd: "We do not want anything killed," and asked those who were carrying guns to leave them behind.