WASHINGTON  A federal grand jury has issued a subpoena to a reporter of The New York Times, apparently to try to force him to reveal his confidential sources for a 2006 book on the Central Intelligence Agency, one of the reporter’s lawyers said Thursday.

The subpoena was delivered last week to the New York law firm that is representing the reporter, James Risen, and ordered him to appear before a grand jury in Alexandria, Va., on Feb. 7.

Mr. Risen’s lawyer, David N. Kelley, who was the United States attorney in Manhattan early in the Bush administration, said in an interview that the subpoena sought the source of information for a specific chapter of the book “State of War.”

The chapter asserted that the C.I.A. had unsuccessfully tried, beginning in the Clinton administration, to infiltrate Iran’s nuclear program. None of the material in that chapter appeared in The New York Times.