Sen. Carl Levin (D-Mich.), chairman of the Senate Armed Services Committee, tells ABC News he is "deeply disturbed" about U.S. aid to Pakistan and has launched an informal investigation into whether high levels of the Pakistani government knew Osama bin Laden's whereabouts.
"We need these questions about whether or not the top level of the Pakistan government knew or was told by the ISI, their intelligence service, about anything about this suspicious activity for 5 years in a very, very centralized place," Levin said in an interview for the ABC News "Subway Series with Jonathan Karl."
Levin, for one, believes high levels of the Pakistani government had to know where Bin Laden was.
"I think at high levels, high levels being the intelligence service, at high levels they knew it," Levin said. "I can't prove it. I just think it's counterintuitive not to."
This year alone the United States gave Pakistan more than $3 billion in military and economic aid.
"Some of it is in our interest. Some of it seems to be, is not clearly in our interest, and that's why the questions that we are asking the Pakistan government to answer need to be answered," Levin said.
As for the U.S. operation to get Bin Laden, Levin said he is unconcerned that details of the story told by the White House have changed.
"There was a firefight on the first floor, and then the most dangerous guy in the world that was being captured on third floor makes a move, which was an evasive move, guns in his room, big guns, you know, powerful guns," Levin said. "And here's a man who sends out suicide bombers, who himself was easily expected could have a suicide vest himself and blow up the whole thing."
Levin added, "The bottom line is the right thing was done in the right way."