At least 6 top Qaeda leaders in Pakistan: US lawmaker

"Of the 20 senior leaders in al-Qaeda , at least a dozen of them, we believe to be travelling around Pakistan someplace," Congressman Mike Rogers, chairman of the powerful House Permanent Select Committee on Intelligence, told reporters at a news conference.

Rogers said US lawmakers would be seeking answers from Pakistan that how Osama bin Laden lived so close to Islamabad. He was killed yesterday in an operation by the US special forces in garrison town of Abbottabad.

"I don't want to speculate if they did or they did not. I mean, we're going to ask those questions. I think Americans have the right to know that. I would like to know hat they knew," Rogers said.

"But at the same time, we have to remember there are still equities that we have in Pakistan as it relates to our national security. We know there are some incredibly bad people there," he noted, adding, it is important for the US that it maintains a relationship Pakistan.

"Keeping a diplomat for 42 days, all of those things -- there's been some speculation in the past about release of information to bad guys through their ISI. All of those things remain a tension for the United States and Pakistan. We hope that we can work our way through it. Doesn't mean that we're not going to ask hard questions," Rogers said.

The powerful Republican Congressman said the information started on this four years ago under George Bush administration.

"I don't draw the nexus between going into Afghanistan and Iraq and not being able to get bin Laden. The reason we had such difficulty is because of his operational security, the way he conducted himself and operated," he said.

At least 6 top Qaeda leaders in Pakistan: US lawmaker

"I mean, think about this, the million-dollar compound plus, which is outlandish by that region of Pakistan that was built to repel any operation just as it happened. No Internet connectivity. They would use cut-outs to cut-outs, meaning they had people who met people they didn't know to deliver a message to another person they didn't know, who eventually worked its way back to Osama bin Laden," he said.

The Congressman said to track bin Laden was "very tricky business".

"And we don't get to walk around every place we want in the world knocking on doors doing an FBI-style investigation about where is somebody," Rogers said.

Hunt on for owner of mansion where Osama was hiding

A massive hunt has been launched for the owner of the sprawling mansion in Abbottabad where Osama bin Laden was hiding in Abbottabad city. The Al Qaeda leader was killed at the $1 million house by US security forces.

The locals used to call the house Waziristan Haveli as it was was owned by a transporter from Waziristan. "Nobody had a clue to the presence of Osama and his family there," Dawn quoted a local resident as saying.

An official said the Waziristani transporters' connection could give them clues as to how Osama and his family travelled to the place. Security agencies are now looking for the mansion's owner.

The house was built some five years ago and it is not far from the Pakistan Military Academy, Kakul.

According to an official, it may have been built close to a high security zone to protect it from foreign intelligence operatives and electronic surveillance and predator drones.

An analyst added: "...that he would live a quiet family life with his wives and children, away from the rugged hot-zones of the tribal regions, in a picturesque and scenic place like Abbottabad was beyond anybody's imaginations."