Washington - The US government is investigating a possible fresh case of mad cow disease according to an official who said in anonymity. It is likely to affect the US cattle industry. Additional checks are being conducted to give the final result.

As a result of this fear, more than 40 countries cut off imports of US beef after a Canadian-born Holstein was found to have been infected in Washington State last December.

This case came to light less than a month after US negotiators reached a tentative agreement between Japan and Taiwan. The American export comes to about US$40 billion a year and if this case is proved, it shall adversely affect the beef industry in America at least for another three months. The foreign market is reported to remain closed for the time being.

However, there is no official confirmation from the US Department of Agriculture (USDA) about the location or origin of the slaughtered animal since it takes about 7 days to get the final result.

According to Alisa Harrison, a USDA spokeswoman, the animal in question was among high-risk animals subjected to the new screening procedures. The animals that died had trouble of walking and showed signs of nerve damage but no quarantines were established.

Federation official Carol Tucker, however, said, "there is no reason for consumers to be alarmed by the announcement."