Police chief Inspector General Khalid Abu Bakar said he had requested countries with citizens on board the plane to investigate their background. He said some had already done this and found nothing suspicious, but he was waiting for others to respond.
Meanwhile, Malaysian authorities said Sunday that the number of countries involved in the search for the missing jetliner has increased from 14 to 25, as the investigation shifted its focus toward the actions of the flight crew.
Hishammuddin said 11 more countries joined the search after it was determined that Malaysia Airlines Flight 370 may have gone as far north as Central Asia, flying over several countries.
This is a significant recalibration of the search,” he said.
Authorities were hoping for more satellite data that would narrow the search, which also includes the Indian Ocean, he said.
That search involves dozens of planes and ships in an ever-widening area where the plane may have gone down. Military and government experts on Saturday pored over satellite and radar data that may shed light on the fate of the plane but so far there is no trace of debris.