In early April, Sen. Charles E. Grassley summoned FBI officials to his Capitol Hill office. He said he wanted them to explain how a program designed to uncover internal security threats would at the same time protect whistleblowers who wanted to report wrongdoing within the bureau.

The meeting with two FBI officials, including the chief of the bureau’s Insider Threat Program, ended almost as soon as it began. The officials said the FBI would protect whistleblowers by “registering” them. When Grassley’s staff members asked them to elaborate, the FBI officials declined to answer any more questions and headed for the door.

“We’re leaving,” said J. Christopher McDonough, an FBI agent assigned to the bureau’s congressional affairs office, said Senate staff members who attended the meeting.

The episode infuriated Grassley (Iowa), a leading advocate for whistleblowers in Congress and the ranking Republican on the Senate Judiciary Committee. Any effort to register whistleblowers, he said, would “clearly put a target on their backs.”

The Insider Threat Program and a continuous monitoring initiative under consideration in the intelligence community were begun by the Obama administration after the leaks of classified information by former NSA contractor Edward Snowden and Army Pvt. Chelsea Manning, and the Navy Yard shootings by Aaron Alexis, who used his security clearance to gain access to the base.

The programs are designed to prevent leaks of classified information by monitoring government computers and employees’ behavior.

Grassley said the episode with the FBI illustrates how federal agencies are setting up internal security programs without giving careful consideration to whether they could dissuade whistleblowers from coming forward.