Kuala Lumpur, Malaysia (CNN) -- A top Malaysian official on Sunday reaffirmed the importance of finding the black boxes of Malaysia Airline flight 370, if the mystery of the missing airliner is ultimately to be solved.
For instance, it would be difficult for investigators to clear crew or passengers until the two recorders are located, Malaysia's acting transport minister, Hishammuddin Hussein, said at a press conference in Kuala Lumpur.
The Inspector General of Police (IGP) has found nothing suspicious with the passenger manifest, Hishammuddin said, but "he did not say that they all had been cleared on the four issues that the police are still investigating, which is the possible hijacking, issues of terrorism, psychological and personal problems.
"That is an ongoing thing, and I don't think the IGP would have meant that they have all been cleared, because unless we find more information, specifically on data in the black box, I don't think any chief of police would be in the position" to declare the cases cleared, he said.
The plane's senior pilot Zaharie Ahmed Shah, 53, has received a lot of attention in the media in the wake of the disaster. Investigators believe it was his voice speaking the last words heard from Flight 370, "Good night, Malaysian 370."
In recent years Zaharie was active on social media, posting videos, in which he explained how to optimize an air conditioning system to reduce electricity bills and showing photos of his many gadgets. He loved food and cooking.
He was also passionate about politics, urging people to vote out the current government. But nothing in his social media posts would necessarily seem to suggest foul play in the MH 370's disappearance.