Visitor passports presented to immigration officers at Singapore checkpoints are screened against Interpol's database of lost or stolen travel documents, said the Immigration and Checkpoints Authority (ICA) yesterday.
And if a passport is one of more than 40 million on Interpol's list, the officer is automatically alerted and the traveller pulled aside for further checks.
This procedure has been in place since May 2008, an ICA spokesman told The Straits Times.
He did not elaborate on how the system works, but security experts said that this verification typically takes just a few seconds.
But despite the fact that checks are quick, Singapore remains one of only a few countries that use Interpol's database to ensure border security, experts noted.
Checkpoint security has come under scrutiny since it was revealed that two passengers on Malaysia Airlines Flight MH370, which disappeared on Saturday, had boarded the plane with stolen passports.
ICA uses biometric technology for identity verification when Singapore citizens and other known travellers opt for automated clearance, which is swifter.
The traveller's thumbprint must tally with ICA's data before the gates open for him to pass through. In this case, there is no need for verification against Interpol's database.
For effective border security, immigration authorities must rely on various levels of checks, said Mr John Harrison, senior analyst at security provider CyberPoint International.
Interpol has long urged member countries to make greater use of its database to stop people crossing borders with false papers but it notes few countries do so.
This is probably because there is no requirement to do so, suggested Mr Harrison.
Countries may also be unwilling to invest in computer systems and software that they would probably need to link up to Interpol's database, experts added.
Terrorism expert Rohan Gunaratna from Singapore's S.Rajaratnam School of International Studies said it should be mandatory for governments to report lost and stolen travel documents, as well as for immigration agencies to screen passenger passports against the Interpol database.
Still, there is no one foolproof system, noted one security expert.
"There are passports that are stolen or lost and never reported and that's why the authorities ultimately rely on several layers of checks. This includes ensuring that ground officers are properly trained and vigilant to look out for suspicious cases," he said.