Australia's Foreign Minister Stephen Smith Tuesday called for clarification from Beijing on tough new visa restrictions imposed on Westerners in the run-up to the Olympics.

Speaking in Hong Kong, where thousands of expatriate business people who deal with companies in southern China have been affected, Smith called on China to explain the crackdown.

Without warning, China at the beginning of April suddenly stopped issuing multiple-entry visas to people travelling from Hong Kong, giving out only single and double entry visas instead.

Applicants have been asked to provide proof of hotel bookings and return tickets before visas are issued, and China has stopped issuing visas on the border as it did in some cases previously.

The sudden change of policy has caused consternation among business people based in Hong Kong who for years have made weekly trips to China using multiple-entry visas.

Tour operators say they have been told by officials that the new restrictions will remain in force until after the Olympics in August, although China has so far not even admitted a policy shift.

Smith, who had a breakfast meeting Tuesday with Hong Kong-based Australian business people, said: "Australia has had an Olympics recently, so we understand the general public policy motivation but it is important there is clarity.

"It is important the Chinese authorities understand the potential practical on-the-ground difficulties that it is causing. We will continue to take the issue up both here in Hong Kong and through our mission in Beijing.

"We want to make sure there are no long-term adverse repercussions for trade and business and industry exchange between Hong Kong and China and between other nation states and China."

Business people and tourists who make regular trips to mainland China from Hong Kong can now only apply for single or double entry visas.

Before the ban, foreigners could get multiple-entry visas for up to three years to visit mainland China from Hong Kong. Multiple-entry visas are widely used by business people and traders.

There has been no official explanation of the policy from China and officials have insisted that multiple-entry visas are still available if the correct criterion are met.

James Tien, leader of Hong Kong's pro-business Liberal Party, has called on both the Hong Kong government and the Beijing government to explain the new policy.

He warned in a newspaper column on Friday that businesses might withdraw their China investments and put money in other regional countries if the restrictions remained in force and were not explained. (dpa)