The former director of the Central Intelligence Agency terminated a secret program to develop hit teams to kill al-Qaeda leaders in 2004, former intelligence officials told the Associated Press.

The officials said George Tenet ended the program because it was not practical.

The plan was later re-instituted by Tenet's successor, Peter Goss. Then in 2006, when Michael Hayden became the CIA's top spy, the program was still facing practical challenges.

The program has come under scrutiny since current CIA director Leon Panetta announced that he canceled the program in June after he learned of its existence.

Panetta also told lawmakers that former vice president Dick Cheney initially directed the CIA not to inform Congress about the program.

The House Intelligence Committee is looking into the possibility of investigating the program and its concealment from lawmakers. 

Last month, the committee asked the CIA to provide documents about the program.