John Bresnahan reports for Roll Call. Excerpt:
FBI agents began fanning out on Capitol Hill in recent weeks, questioning Senators serving on the Intelligence Committee as part of an unprecedented effort to find out who leaked classified information from the Congressional probe of intelligence failures prior to the Sept. 11 terrorist attacks.
FBI officials are also asking Hill staffers caught up in the investigation to submit to polygraph examinations, according to Congressional sources.
…
FBI agents are asking the staffers if they would undergo polygraphs, although the number of staffers who have actually been tested so far cannot be determined. No similar requests have been made of lawmakers who serve on the panels.