Final tests of a pig suspected of being infected with swine fever have proved negative, according to the Danish Veterinary and Food Administration. Preliminary tests of another suspected case of swine fever were also negative.

"The final result of the laboratory tests associated with the suspicion on 24 September in a pig herd near Kolding does not show any presence of classical swine fever," said the regulator.

Last week, leading pork exporter Danish Crown closed down one of its biggest slaughterhouses in Blans, Denmark. A pig, which arrived at the plant dead, showed some symptoms of swine fever.

A detailed examination of the animal also indicated swine fever in the pig's inner organs. As a precaution, the authorities decided to close the slaughterhouse.Another unit in Odense was closed on Friday.

Preliminary results of tests from this pig are however negative, and the final results are due tomorrow.

The disease has a high mortality rate in young pigs but is not dangerous to humans. Denmark, which has not suffered from serious swine fever since 1933, is the world's leading pig meat exporter, with sales of around 24 billion Danish crowns abroad a year.

Danish Crown has already been hit by swine fever scares this year, only to have them disproved one hour later after the suspected pig had been thoroughly examined.

A range of special measures have been introduced at a number of slaughterhouses, including baths and special disinfection of footwear before employees leave the slaughterhouse after work. Each employee has also been given detailed information about avoiding spreading potential infection from the slaughterhouse.