Arriving at the agency's M Street office in Washington before 11 a.m., the agents served grand jury subpoenas seeking testimony and records from 17 current and former agency employees before carrying out boxes of documents and computers around 5 p.m.
The raid was the latest step in the long investigation of Special Counsel Scott Bloch, who heads the independent office that enforces workplace laws at federal agencies. For more than 36 months, the Office of Personnel Management's inspector general has been probing allegations by former OSC employees who say Bloch retaliated against them for opposing his policies for handling discrimination charges based on sexual orientation.
Last year, the OPM IG's office began looking into Bloch's hiring of private computer technicians to remove files from his office computer and those of aides. The files had been sought by investigators, but Bloch has described the files as personal and not relevant to the probe.
The participation of the FBI and the grand jury, which is empaneled in Washington, indicates investigators are weighing criminal charges related to the IG probe, such as obstruction of justice.
But OSC employees said the grand jury subpoenas seek a wide range of information that goes beyond Bloch's deletion of computer files or treatment of agency employees.
Investigators have demanded all files on OSC's investigation last year into allegations of improper political activity by Lurita Doan, the former head of the General Services Administration, who was forced to resign last week by the White House.
OSC found that Doan, in a January 2007 meeting to discuss Republican congressional races with the agency's political appointees and a White House political operative, violated the Hatch Act, which bars federal employees from using government resources for partisan politics. But the finding generated criticism from House Republicans, who accused Bloch of leaking results of the Doan investigation to the news media.
Republicans and other critics also have criticized Bloch for launching a wider investigation into political briefings White House officials conducted across the federal government. They have accused Bloch of trying to use the probe as leverage against possible moves by the White House to force his ouster due to his conduct at OSC.
During Tuesday's raid, investigators did not seek files from the wider Hatch Act probe, but they subpoenaed at least two OSC employees who are part of the unit looking into the suspected political activities. They also sought Bloch's expense and credit card records, information regarding his use of storage facilities or safety deposit boxes and material related to testimony he has delivered at congressional hearings.
In addition, investigators demanded documents related to OSC's investigation into allegations that Secretary of State Rice used federal resources to travel to campaign appearances supporting President Bush's re-election in 2004. Bloch's office closed the case, finding no violation by Rice.
Sources said the FBI searched Bloch's home in Fairfax County, Va., while his wife and children were there.
The FBI confirmed that its agents had executed search warrants but declined to elaborate. A spokeswoman for the agency's Washington field office said documents in the case are sealed.
An OSC spokesman said the office is cooperating with investigators but added that OSC employees were unsure of the reasons for Tuesday's raid. Agents questioned Bloch upon arriving at the office in the morning, interrupting him while he was on the phone, the spokesman said.
Bloch declined to comment as he left his office Tuesday evening.
After learning of the FBI raid, House Oversight and Government Reform ranking member Tom Davis urged Oversight and Government Reform Chairman Henry Waxman to subpoena Bloch to obtain a sworn deposition regarding his deletion of computer files.
Davis released a transcript of an informal March 4 interview of Bloch by committee staff in which Bloch refused to answer questions, such as who suggested he hire technicians to scrub his computer.