Malaysian Inspector General of Police Khalid Abu Bakar said Wednesday that all the passengers on board the missing MH370 flight had been "cleared" of hijacking, sabotage or having psychological or personal problems by the police, according to the Malaysian state news agency Bernama.

The investigation has freed the 227 passengers from the four elements, he said.

"They have been cleared of the four (elements). It (is) according to our own procedure (investigation)," Khalid said after officiating a seminar for the police.

He said the cabin crew, including the pilot and the co-pilot, are still being investigated in these four areas.

Khalid said the police have so far recorded statements from over 170 individuals on the incident, adding that more statements would be recorded.

He said the police would not release any findings of the investigation in case it would jeopardize the ongoing probe.