Beginning Oct 1, US immigration inspectors will subject travellers who have made but are not able to give credible reasons for their previous visits to Malaysia to "special registration measures".

The US Department of Justice's four-page memo dated Sept 5 did not specify what the measures were but said the new policy will be implemented "in a phased approach beginning on Sept 11 and expanded on Oct 1".

The memo has been posted on the Internet ( Page 1 , 2 , 3 , 4 ).

"These criteria may be updated routinely in the future based on current national security, law enforcement or intelligence information," the memo added.