Washington ? The FBI has intensified its probe of a classified intelligence leak, asking 17 senators to turn over phone records, appointment calendars and schedules that would reveal their possible contact with reporters.

In an Aug. 7 memo passed to the senators through the Senate general counsel’s office, the FBI asked all members of the Senate Select Committee on Intelligence to collect and turn over records from June 18 and 19. Those dates are the day of and the day after a classified hearing in which the director of the National Security Agency, Lt. Gen. Michael V. Hayden, spoke to lawmakers about two highly sensitive messages that hinted at an impending action that the agency intercepted on the eve of Sept. 11 but did not translate until Sept. 12.

The request suggests that the FBI is now focusing on the handful of senior senators who are members of a Senate-House panel investigating Sept. 11 and attend most classified meetings and read all the most sensitive intelligence agency communications. A similar request did not go to House intelligence committee members.

The request also represents a much more intrusive probe of lawmakers’ activities, and comes at a time when some legal experts and members of Congress are already disgruntled that an executive branch agency, such as the FBI headed by a political appointee is probing the actions of legislators whose job it is to oversee FBI and intelligence agencies.

The FBI declined to comment. Most senators are away for the August recess, but Sen. Bob Graham, D-Fla., who heads the Senate intelligence committee, said through a spokesman that he was cooperating with the investigation and had asked staff members to gather the requested records.

In recent weeks, FBI agents finished questioning nearly 100 people, including all 37 members of separate House and Senate intelligence committees and some 60 staff members. At the conclusion of their interviews with members and staff, FBI agents typically asked them if they would be willing to take polygraph tests. Most declined.