PARIS – Interpol knew about stolen passports that two passengers used to board an ill-fated Malaysia Airlines flight bound for China, but no country checked the police agency's vast database on stolen documents beforehand, it said Sunday. Interpol said it hopes authorities will "learn from the tragedy."

It's not known whether ­stolen passports had anything to do with Saturday's disappearance of the Boeing 777 bound from Kuala Lumpur, Malaysia, to Beijing with 239 people on board. But such oversights aren't new.

Last year, passengers boarded planes over a billion times without their passports being checked against Interpol's database of 40 million stolen or lost travel documents, said the international organization based in Lyon, France.

Only few countries check

Interpol has sounded the alarm on the issue for years, and just last month it bemoaned that "only a handful of countries" regularly use its stolen or lost travel documents database of records from 167 countries. For example, the database was searched more than 800 million times last year — but one in eight searches was conducted by United Arab ­Emirates alone.

On Sunday, Interpol Secretary General Ronald Noble said his organization has long asked why countries would "wait for a tragedy to put prudent security measures in place at borders and boarding gates."

"Now, we have a real case where the world is speculating whether the stolen-passport holders were terrorists, while Interpol is asking why only a handful of countries worldwide are taking care to make sure that persons possessing stolen passports are not boarding international flights," he said.

Noble said he hopes "that governments and airlines worldwide will learn from the tragedy of the missing flight and begin to screen all passengers' passports before allowing them to board flights."

The declared thefts of the two passports used — one of Austrian national Christian Kozel in 2012, and one of Luigi Maraldi of Italy last year — were entered into Interpol's database after they were stolen in Thailand, the police body said.

Interpol also said it and national investigators are examining other suspect passports and working to determine the true identities of those who used the stolen passports to board the Malaysia Airlines flight.

In an interview with the Associated Press in 2010, Noble had warned that "the greatest threat in the world" then was a half-billion international air arrivals that took place in which travel documents were not compared against Interpol databases.

In November, in yet another talk on the subject, Noble said that four of every 10 international passengers are still not screened against the Interpol database, which produced more than 60,000 hits in 2012.

Some countries have woken up to the threat more than others. In 2006, U.S. authorities scanned the Interpol database about 2,000 times — but did so 78 million times just three years later.

Interpol is now reaching out to the private sector. It's preparing an initiative called "I-Checkit" that will let businesspeople in the travel, banking, and hospitality industries screen documents against the lost-documents database when customers book a flight, check into a hotel room or open a financial account.