THE foot-and-mouth epidemic brought Britain's livestock industry to a standstill last night as a week-long ban was slapped on moving animals vulnerable to the disease.

The ban on transporting cattle, pigs, sheep and goats was announced as growing evidence emerged that the potent virus was spreading across the country - having started in the North-East.

Pigs at a farm in Northumberland were confirmed as suffering from the disease, and a cattle farm a few miles away was also believed to be infected.

An abattoir and three farms in Essex have also been hit, and a dead cow displaying symptoms similar to foot-and-mouth disease has been found in Northern Ireland.

Chief veterinary officer Jim Scudamore said the likely source of the outbreak was now believed to be the pig farm at Heddon-on-the-Wall, near Newcastle.

The farm regularly delivered pigs to the Essex slaughter house where the disease was first discovered. All 500 pigs will be slaughtered.

The Government revealed that the first pigs to be infected may have been suffering from foot-and-mouth for more than two weeks before the disease was discovered.

It was believed the disease may have entered Britain a month ago, as questions were asked as to why it had taken so long to detect the virus.

Bobby Waugh, 55, who runs the infected farm at Heddon-on-the-Wall with his brother Ronnie, said last night: "This is devastating news, not just for me, but for the whole industry.

"I have no idea where the disease has come from. I honestly hadn't seen anything wrong with any of my pigs in the last few weeks. How could I report something I didn't see?"

He said the farm had received a clean bill of health when a Ministry of Agriculture inspector and trading standards officer carried out an annual check-up in January.

The disease appears to have spread from there to cattle at Prestwick Hall Farm four miles away, in Ponteland.

There, farmer Ian Williamson, 65, stressed last night he had no confirmation that his animals had been infected. He faces an anxious 24 hours before the results of tests carried out on his livestock are known.

He said: "I don't think I'll sleep much tonight."

Richard Watts, group secretary for Darlington National Farmers' Union, said they were "very concerned" for their members.

"They are in a very distressing situation at the moment, particularly those who have got the disease," he said.

More than 600 farms known to have supplied the Cheale Meats abattoir in Essex with live animals were under observation last night.

Announcing yesterday's ban on transporting livestock, Agriculture Minister Nick Brown said: "There is going to be a complete standstill for the next seven days in the movement of livestock in Great Britain.

"The purpose is to prevent the spread of foot-and-mouth disease while we are trying to extinguish it."

David Maughan, 55, who has 410 beef cattle and free-range poultry at his farm in Morton Tinmouth, near Darlington, said the ban was a "bold move" but sensible. "It was something which needed to be done," he said.

"But we're all very nervous. When you hear that the farm probably had it for 14 days, possibly longer, the potential for infection to spread is enormous.

"It's surprising it hasn't burst loose before."

Livestock traders said they supported the ban, even though it would cause "significant difficulties" to their £25m-a-week business.

Mr Brown reiterated assurances that farmers would be compensated for any animals slaughtered to stop the spread of the disease at full market value, but said that the Government would not pay for any consequential loss.

He also pointed out that it was a criminal offence not to notify an outbreak of foot-and-mouth disease on a farm, with a maximum penalty of £5,000 in the magistrates' court.