THE deliberate release of viral material, possibly in an act of sabotage, may have caused the foot-and-mouth disease outbreak in southern England, officials said last night.

England's Health and Safety Executive said in a report ordered by Prime Minister Gordon Brown that "release by human movement [of the FMD virus] must be considered a real possibility." This could have been deliberate or accidental.

Inspectors all but discounted theories that the virus escaped by air or water from the laboratory complex close to where the outbreak started. They were, however, continuing to investigate the possibility of equipment failure.

The HSE concluded in the report that there was "a strong probability" the virus came from the research centre three miles from the first outbreak in a herd of cattle in Surrey.

The report came as British farmers warned last night that there would be "hell to pay" if the decision to send culled cattle 80 miles for incineration led to the spread of foot-and-mouth disease.

A further 102 carcasses from the outbreak in Surrey were due to be destroyed at the Wessex Incineration plant near Frome, Somerset, last night.

The Prime Minister insisted last night that efforts to contain and eradicate foot-and-mouth disease would continue apace.

Speaking after health and safety officials failed to pinpoint the source of the outbreak, Mr Brown praised the "determined" operation to stop it spreading.

Last night, a "keep out" message was fixed to the gates of the incineration plant which lies in open countryside near the village of Tytherington.

"My pigs are only about 800 yards away from the incinerator," said Patrick Twigger (41), who owns nearby Monksham Farm. "It's crazy that these cows have been transported across the country and so close to my farm. If the transporter lorry has a leak or a crash, God knows what will happen.

"After what happened in 2001, I am amazed there isn't a mobile incineration machine which can go straight to the infected farm in Surrey."

James Salmon, who has 350 cattle at a farm in Tytherington, about half a mile from the plant, said: "We have got to hope they have got it right. If there is an outbreak here there will be hell to pay, and hopefully there will be a lot of compensation."

Wept

Meanwhile, the second farmer to fall victim to the foot-and-mouth outbreak wept yesterday as he told how his business had been wiped out after his cattle contracted the disease. John Gunner, 60, said his herd of Charollais and Sussex cows, which were grazing on three separate sites, have had to be slaughtered after he noticed signs of the infection in his animals on Monday.

He revealed that they had been given a clean bill of health only a day before by vets. Mr Gunner rented 300 acres around the village of Wood Green, near Guildford, Surrey, just a few miles from the first infected farm at Normandy, owned by the Pride family.

Speaking at his semi-detatched home, where he lives with his wife, Joy, he said: "It is a terrible disaster and I just hope no one else goes through this. It has just wiped us out. It is our only income and I am just devastated. I will try and recover but it will be difficult."

Mr Gunner said that he was concerned when news broke last Friday that foot-and-mouth had been discovered at the Pride family farm and said he checked his herd every three hours.

Mr Gunner said he checked the cattle again on Monday morning on all three of his sites and all seemed fine but by lunchtime he sensed that something was not quite right.

He said: "One was limping and another was dribbling at the mouth. We got back in touch with the veterinary people and they returned.

"By this point my old bull, Ned, wasn't very well. He had great pedigree and was so gentle I could put my arms around him. In the short time I was there he collapsed in front of my eyes. It was just so fast."

When asked what he would feel if the disease was found to have leaked from the laboratory site at Pirbright, Mr Gunner said: "I would feel annoyed that people who are dealing with such dangerous diseases are so irresponsible.

"I know that it is a necessity but there should be strict controls and it should not have been allowed to get out."

Meanwhile, the cattle farmer at the centre of the foot-and-mouth outbreak told of how his family had been "living through a nightmare" as he described how the disease had shattered his livelihood.

Roger Pride said his "whole world had been turned upside down" by the discovery of the virus in his herd and told how his business would be closed for months.

- Lewis Smith, Graham Tibbetts and Will Pavia