Japan has asked the US and 25 other beef exporters to provide country-of-origin certificates for beef shipments in order to help prevent the spread of BSE, or mad cow disease.

Government officials said the request follows on from concerns that the US may export beef that may have originated in Canada, where a single case of mad cow disease was discovered in May.

Japan's Agriculture, Forestry and Fisheries Ministry sent a letter to 26 countries, including Australia, Chile, Mexico, New Zealand and the US, informing them of the decision which will apply to shipments as from 1 July, an official told Reuters.

Japan's beef industry was severely hit by an outbreak of the disease there in 2001 and consumer demand for beef has only recently begun to recover.