The Ministry of Agriculture and Forestry said Wednesday the South Korean government has stopped imports of U.S. beef and beef products following the report of a suspected case of mad cow disease in the state of Washington earlier this week.

The ministry said it has decided to suspend customs clearance for all U.S. beef and beef products at the nation's ports to stave off the possible spread of mad cow disease in South Korea. A halt of customs clearance is considered a virtual import ban.

In addition, the ministry instructed that the circulation of U.S. beef and beef products stored in quarantine warehouses be suspended, while considering an inspection of American beef already in circulation.

A ministry official said the suspension of customs clearance had been instructed because the results of the U.S. government's own examination on the matter have not yet been completed. Seoul will decide whether or not to levy a formal import ban depending on the outcome of the ongoing examination.

At present, South Korea has bans on beef imports from Britain, France, Japan, Canada and 15 other countries hit by mad cow disease in the past. As a result, Australia has now become the last remaining major beef exporter with access to the domestic market here.