Washington ? Agents from the FBI and the Office of Personnel Management Tuesday raided the headquarters of Special Counsel Scott J. Bloch as part of a probe into whether he obstructed justice by having his computer files erased.

Bloch, a former Lawrence attorney, was served with a subpoena to appear before a federal grand jury in Washington, and about 17 other employees were served as well, according to a source who has seen the subpoenas.

Agents also raided Bloch’s home in Fairfax County, Va., hauling away boxes of files.

James P. Mitchell, a spokesman for the Office of Special Counsel, said the agency is cooperating with the investigation.

“We really don’t know what this is about,” Mitchell said. “The subpoena is very broad, and it covers a lot of territory.”

Bloch was nominated by President Bush in June 2003 to head the Office of Special Counsel, an agency responsible for protecting the rights of federal workers, ensuring that whistle-blowers are not subjected to retaliation and investigating improper political activities on government property.

There he became the target of an investigation into allegations that he had retaliated against whistle-blowers on his staff and improperly dismissed whistle-blower cases brought to the agency by others. The White House asked the Office of Personnel Management to look into those allegations in 2005.

According to the source who has seen the subpoenas, the wide range of files that the FBI wants to see includes documents relating to the special counsel’s investigation of Lurita Alexis Doan, who resigned last month as head of the General Services Administration, as well as an older investigation of Secretary of State Condoleezza Rice that has since been closed.