Former Homeland Security Secretary Michael Chertoff warned on Sunday that the missing Malaysian jetliner highlights the issue of “inside threats.”

Chertoff discussed the theories that the pilots or crewmembers might be responsible for its disappearance in an interview on NBC’s “Meet the Press.” 

“We face the question of inside threats,” he said. “I think the issue of screening and understanding people when they go off the rails inside enterprises is going to become more of an issue.”

Edward Snowden was another example of an inside threat, said Chertoff, who headed the Department of Homeland Security from 2005-2009 under President George W. Bush.   

As the search for the plane enters its third week, he said the core issue is deepening the investigation into the background of the pilots.

“One of the questions is whether the Malaysians were completely forthcoming at the very beginning,” he added, referring to their knowledge of radar data.

In a separate interview on the show, Rep. Mike Rogers (R-Mich.) said he believes the plane is at the bottom of the ocean.

“I do believe that it’s likely and probable that it crashed into the Indian Ocean,” but added officials can’t eliminate other theories yet.