Canada has asked South Korea to disclose any scientific evidence used in Seoul's decision to ban Canadian beef in June 2003, due to concerns over mad cow disease, a South Korean official said Saturday.

In an official letter sent to the South Korean Embassy in Geneva on January 19, the Canadian Embassy in the city said the South Korean government's move to ban imports of Canadian beef violated Article 3 of the World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures, he added.

Article 3 stipulates "Members (of the WTO) shall base their sanitary or phytosanitary measures on international standards, guidelines or recommendations."

Canada also urged South Korea to specify the scientific and legal grounds for imposing the ban by February 19, citing Article 5, Clause 8 that says an explanation of the reasons for sanitary or phytosanitary measures may be requested and shall be provided by the member maintaining the measure.

The North American country has claimed that South Korea imposed the ban without conducting scientific examinations.

"It was rare for Canada to send a letter requesting an official explanation (on our ban on Canadian beef imports), referring to the article related to the WTO agreement and setting a date," a senior South Korean trade official on a visit to Davos said.

"If Canada is dissatisfied with our answer or we can't meet the deadline for replying to Canada's questions, the country is likely to file a complaint with the WTO," he said.

The Foreign Affairs and Trade Ministry and the Agriculture and Forestry Ministry are drawing up measures to deal with Canada's request, but the South Korean government reportedly did not conduct a scientific investigation before placing a total ban on Canadian beef imports.