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Whistle-blower Coleen Rowley has been scheduled to testify in the Senate this week about her deep dissatisfaction with FBI headquarters, but she will not talk in detail about the terrorism case at the root of her complaints, officials said Friday.

Rowley, general counsel of the FBI’s Minneapolis field office, is expected to appear before the Senate Judiciary Committee on Thursday, along with FBI Director Robert Mueller and Inspector General Glenn Fine, sources said.

But Rowley, joined by senior officials at FBI headquarters, said she would testify only in general terms that do not interfere with the prosecution of alleged terrorist conspirator Zacarias Moussaoui, who faces trial, sources said.

Some lawmakers may seek to have Rowley publicly identify officials at headquarters who allegedly hampered the investigation of Moussaoui, a French national arrested on immigration charges in August after he raised suspicions at a flight school outside Minneapolis.

Rowley, a 47-year-old known for her candor, alleges that Washington bureaucrats resisted seeking a special intelligence warrant to search Moussaoui’s laptop computer, even altering the application for such a warrant and scolding Minneapolis agents after they sought help from the CIA in frustration.

Outlined in a blistering 13-page letter delivered to Mueller and congressional intelligence committees, her complaints have thrust Rowley into the center of an intensifying debate about the failure to detect possible warning signs before Sept. 11.

Congressional sources said Rowley was first approached about testifying May 24 in the form of a congressional witness protection letter, notifying her of the right to testify without fear of retaliation. Rowley has sought protection under federal whistle-blower laws.

In her May 21 memo, Rowley said officials at FBI headquarters in Washington “continued to, almost inexplicably, throw up roadblocks and undermine” efforts to obtain a warrant.

Sen. Charles Grassley (R-Iowa), a frequent FBI critic, said Friday that he thought some details should be fair game, including “what she knows about middle management at headquarters stonewalling. … The people who stonewalled, their heads should roll.”

Grassley said he thought Rowley could be an effective witness even if she could not speak directly about the Moussaoui case. “She can tell us an awful lot about the culture of the FBI,” he said.

In her letter to Mueller, which was also delivered to congressional intelligence committees, Rowley alleged that the FBI might have been able to stop some of the Sept. 11 hijackers if headquarters officials had been more aggressive in pursuing an investigation of Moussaoui.

Rowley said officials resisted requests for a secret warrant to search Moussaoui’s laptop, which was later found to include a crop-dusting manual, jetliner information and a reference to a man since identified as a key operative in the plot.

She accused one supervisory agent in particular of “consistently, almost deliberately, thwarting the Minnesota FBI efforts.” Law-enforcement officials have identified that person as Michael Maltbie, a supervisory special agent recently transferred out of counterterrorism to the Cleveland field office.

Mueller, who took the helm at the FBI on Sept. 4 and has pledged to remake the bureau to focus on preventing terrorism, has publicly thanked Rowley for her letter and promised that she would suffer no reprisals. Mueller has referred the case to Fine’s office for investigation.

A spokesman for Fine said Friday that the inspector general’s office had opened a separate review of the problems arising in the Moussaoui case, as well as the apparent failure of FBI officials to heed a letter last summer from a Phoenix agent warning that terrorists might be training in U.S. flight schools.