Tensions Over F.B.I.’s Work on Hamas Case Spill Into the Open

When the Justice Department demanded all the names of F.B.I. personnel who had worked on investigations into the Capitol riot on Jan. 6, 2021, it made a similar request about a high-profile terrorism case involving Hamas.

But why the department’s acting deputy leader, Emil Bove III, sought the information remained unclear, leaving agents and prosecutors to wonder what spurred his interest in a case that had led to criminal charges against Hamas’s leadership last year.

Its inclusion touched on a simmering dispute that has pitted the Federal Bureau of Investigation’s office in Washington against prosecutors at the U.S. attorney’s office in Manhattan and the main Justice Department, people familiar with the investigation say, escalating what appeared to be bureaucratic infighting into an ugly public spat. It has intensified scrutiny on the F.B.I. as the Justice Department has made clear its intent to shake up the bureau.

“The Justice Department is looking into why F.B.I. agents at the Washington field office were resisting efforts to progress the Hamas investigation,” a Justice Department official said in an unusual public statement. “Federal prosecutors had to elevate their concerns to a supervisory level to get them to take the requested investigative steps.”

The F.B.I. declined to comment.

After Hamas militants attacked Israel on Oct. 7, 2023, the Justice Department sought to investigate Hamas, a designated terrorist group, prompted in part by the sheer number of Americans who had been killed or kidnapped in the assault. Forty-seven Americans were slain while eight more were taken hostage in Gaza.

Tensions flared from the start, including over which office would take the lead.

The F.B.I.’s field office in Washington and prosecutors in the capital typically have jurisdiction over cases involving the Middle East and made clear they would pursue charges. But prosecutors at the U.S. attorney’s office in the Southern District of New York quickly came up with their own charges against Hamas leaders based only on their public statements, three former senior law enforcement officials said, catching the F.B.I. off guard.