The discovery that two passengers boarded the missing Malaysian jet using stolen passports reveals flaws in the screening of air travelers that persist more than 12 years after security worldwide was strengthened in the wake of the Sept. 11 terror attacks.

More than 40 million passports are listed as missing on a database created by Interpol in 2002, yet the international police agency says planes were boarded more than a billion times last year without the travel documents being screened against the register.

The lack of international consistency in checking passports may explain how two people were able to board Malaysian Airline System Bhd Flight 370 in Kuala Lumpur using passports that were reported stolen by European citizens in Thailand.

While there is no evidence that the two passengers had any connection to the March. 8 disappearance of the Boeing Co. 777-200 en route to Beijing, the security breach should be a rallying call for governments to act, according to Rohan Gunaratna, head of the S. Rajaratnam School of International Studies’ International Center for Political Violence and Terrorism Research in Singapore.

Systematic Searches

“Certainly Malaysia should have checked the existing Interpol database of lost and stolen passports,” he said. “It should be mandatory for governments to input all lost and stolen passports and it should also become mandatory for all immigration and security agencies to screen all passengers against it.”

The use of stolen passports spurred concerns that the disappearance of the plane, which was carrying 239 people, from radar screens may be connected to terrorism. Austria and Italy said passports used by two male passengers on the plane were stolen from their citizens.

Closed-circuit television footage exists of the two people who used the false passports, Azharuddin Abdul Rahman, director general of the Department of Civil Aviation, said yesterday. Malaysia today said it had identified one of the passengers, without giving details.

“We are trying to ascertain if the two holders of false passports entered Malaysia, legally or illegally,” Inspector- General of Police Khalid Abu Bakar said in a mobile-phone text message.

Pickpocketing Rife

Passport theft or loss is common in Thailand, with Russian, British and French passports the most commonly reported as missing last year, according to data from Thai police. Some 2,475 losses were reported from the top 10 nationalities combined, data show.

Stolen passports have been an ongoing problem in Southeast Asia, where pickpocketing is relatively rife, Chris Yates of Yates Consulting, a Bolton, U.K.-based aviation security consulting firm said by phone.

“Without a doubt, this is a wake-up call,” Yates said. “An identity is a very marketable currency and you want to be sure the person standing in front of you with a wad of notes or the person buying an airline ticket is who they really say they are.”

Lyon, France-based Interpol, has warned since at least 1973 about the increased use of counterfeit passports as international tourism boomed. Criminals have made and used false passports and altered authentic travel documents for uses including for trafficking and smuggling, the agency said.

Reported Stolen

The two Austrian and Italian passports were added to Interpol’s stolen database after their theft in Thailand in 2012 and 2013 respectively, the agency said in a statement yesterday. No checks of the passports were made by any country between the time they were entered into the database and the departure of the flight from Kuala Lumpur, it said.

Only a few countries systematically search Interpol’s databases to determine whether a passenger is using a stolen or lost travel document, the agency said in the statement. More than 800 million searches are conducted annually, and stolen or missing passports are found an average of 60,000 times a year, Interpol said.

The U.S. searches the database more than 250 million times a year, while the U.K. conducts more than 120 million searches and the United Arab Emirates searches more than 50 million times, it said.

The use of stolen passports sends a “red flag” that terrorism may have played a part, said New York Republican Representative Peter King, who is a member of the House Intelligence and Homeland Security committees. There needs to be a “full scrub” of everyone on the flight, and U.S. intelligence agencies are working with their counterparts in Asia, King told Bloomberg News.

Crashing Planes

No evidence exists of terrorism at this point, said a U.S. official following the case who asked not to be identified because the investigation is in its early stages.

“If Malaysia Airlines and all airlines worldwide were able to check the passport details of prospective passengers against Interpol’s database, then we would not have to speculate whether stolen passports were used by terrorists to board MH370,” Interpol’s Secretary General Ronald K. Noble said in a statement posted on the agency’s website yesterday.

Current rules restricting Interpol’s disclosure of information only to governments — and not airlines or other third parties — hamper efforts to uncover such stolen documents, said Trevor Long, former general manager of Group Facilitation at Qantas Airways Ltd.

The Australian, New Zealand and U.S. governments do a good job of notifying airlines when to stop a person from boarding, Long said. Other countries, including Malaysia, don’t follow the same procedure, he said.

Sometimes “it’s done more for show,” with airlines providing the data and the government workers not doing anything with it, Long said.