Farmers have breathed a sigh of relief after the first set of tests to determine if a rare pig disease has resurfaced proved negative.

The Department for Environment, Food and Rural Affairs made the announcement after blood samples were taken from pigs at one farm in West Sussex and other counties at the weekend.

But today a spokesman would not confirm whether these results included the West Sussex farm.

He said: "The initial results from the first set of blood tests taken at the weekend have proved negative.

"We are not saying which farms this includes at this stage because investigations are ongoing.

"More tests were taken yesterday and we will be monitoring the situation closely in the next 48 to 72 hours."

The pig disease was wiped out in the UK 11 years ago.

But it was recently discovered at the same Essex abattoir where the first case of foot-and-mouth was detected last year.

Defra said routine testing in pigs resulted in six positive tests for Aujeszkys disease.

The farms being tested, including the one in West Sussex, were ones which the pigs may have originated from.

A spokesman said: "We got six quite strongly positive results at the farm in Essex, which was unusual.

"So we traced the pigs back to certain farms. Initial testing suggests there is no sign of disease.

"The farms may have had the disease but don't have now. Or the six positives may have been false laboratory readings.

"They were strong positives and that is why we are still investigating."