Officials say they are planning to cull more than one million pigs, three times the number they initially planned to slaughter.

The Japanese encephalitis (JE) virus, which is transmitted from pigs to humans via mosquitoes, has been blamed for 63 deaths in the state of Negri Sembilan.

Simon Ingram reports: " More than a million pigs are now to be destroyed"

Scientists are also fighting the spread of a second pig-borne virus. It existence was confirmed only last week.

A national task force battling the two viruses said the extended cull will include healthy animals. They are being sacrificed to save the estimated 1.7m pig in the rest of the country.

More than 95,000 pigs have already been slaughtered to contain the spread of JE and the new virus.

Officials say they know very little about the new disease. It is said to have characteristics similar to the Hendra virus, which killed two people and 15 horses during outbreaks in Australia in 1994 and 1995.

Health Minister Chua Jui Meng, quoted by the national Bernama news agency, said: "The main problem to our mind is the Hendra-related virus.

"At the same time, we must not forget the preventive and control measures for JE."

Foreign experts have been invited to Malaysia to investigate the new strain of virus that has been detected.

Many farmers abandoned their animals and fled in panic as the number of JE cases rose by the day.