A senior U-S senator says the Central Intelligence Agency has been illegally searching computers of the staff and members involved in a probe into a C-I-A interrogation program. Dianne Feinstein has expressed concern that the C-I-A's search may well have violated the separation of powers' principles embodied in the United States Constitution. The CIA has denied it has spied on the Senate. The U-S intelligence agencies-- particularly the National Security Agency, the NSA have already been accused of espionage activities against U-S citizens. This has drawn condemnation from rights groups, including the American Civil Liberties Union.