WASHINGTON -- A behind-the-scenes battle between the CIA and Congress erupted in public Tuesday as the head of the Senate Intelligence Committee accused the agency of breaking laws and breaching constitutional principles in an alleged effort to undermine the panel's multi-year investigation of a controversial interrogation program.
Chairwoman Dianne Feinstein, D-Calif., accused the CIA of secretly removing documents, searching committee-used computers and attempting to intimidate congressional investigators by requesting an FBI inquiry of their conduct -- charges that CIA director John Brennan disputed within hours of her appearance on the Senate floor.
Ms. Feinstein described the escalating conflict as a "defining moment" for Congress' role in overseeing the nation's intelligence agencies and cited "grave concerns" that the CIA had "violated the separation-of-powers principles embodied in the United States Constitution."
Mr. Brennan fired back at a previously scheduled Washington speech, saying, "When the facts come out on this, I think a lot of people who are claiming that there has been this tremendous sort of spying and monitoring and hacking will be proved wrong."
The dueling claims exposed bitterness and distrust that have soared to new levels as the committee nears completion of a 6,000-page report expected to serve as a scathing historical record of the agency's use of waterboarding and other brutal interrogation methods on terrorism suspects held at secret CIA prisons overseas after the attacks of Sept. 11, 2001.
Displaying flashes of anger during her floor speech, Ms. Feinstein said her panel would soon deliver the report to the White House, and push for declassification of a document that lays bare "the horrible details of the CIA program that never, never, never should have existed."
The latest dispute is in some ways a proxy for a deeper conflict over that document. The CIA and the committee are at odds over many of the report's conclusions about the interrogation program's effectiveness, but are battling primarily over tension that surfaced during the inquiry.
Ms. Feinstein's remarks provided the most detailed account of that investigation, describing an arrangement in which the CIA set up a secret Northern Virginia facility with a set of computers where committee investigators were promised unfettered access to millions of operational cables, executive memos and other files on the interrogation program.
The discord between Ms. Feinstein and Mr. Brennan centers on whether agency employees or committee staff members -- or both -- abused their access to that shared network to gain an upper hand.
Ms. Feinstein implied that the CIA sabotaged the committee's efforts from the outset, loading a massive amount of files on computers with no index, structure or ability to search. "It was a true document dump," she said.
Over a period of years, investigators pored over more than 6.2 million classified records furnished by the CIA, using a search tool that agency technical experts agreed to install.
But U.S. officials said the committee gained access to a set of documents that the agency never intended to share, files that were generated at the direction of then-CIA director Leon Panetta as part of an effort to take an inventory of the records being turned over to Ms. Feinstein's panel.
The two sides have engaged in heated exchanges in recent days over the nature of those files and how they were obtained.
Referring to them as the "Panetta internal review," Ms. Feinstein insisted that committee staff members discovered the documents during an ordinary search of the trove. She said they are particularly valuable because in tracking the flow of documents, CIA employees in some cases drew conclusions about their contents that matched subsequent interpretations made by committee staff members.
Jeremy Bash, Mr. Panetta's former chief of staff, said Tuesday that was never the director's intent. Mr. Panetta "did not request an internal review of the interrogation program," he said.
Meanwhile, a letter Mr. Brennan distributed to the CIA workforce Tuesday raised questions about Ms. Feinstein's claims and her awareness of how and when the panel obtained the so-called Panetta review files. The letter, which Mr. Brennan sent Jan. 27 to Ms. Feinstein and which he attached to a message sent to the workforce, recounts a meeting they had weeks earlier to discuss the matter. Ms. Feinstein said then she didn't know that the committee already had copies of the Panetta review. Mr. Brennan pushed her to say why the panel had recently requested the files when they already had them.
"You informed me that you were not aware that the committee staff already had access to the materials you had requested," Mr. Brennan wrote, according to a copy obtained by The Washington Post. Mr. Brennan urged Ms. Feinstein to work with the agency to determine how the committee had obtained the documents, a request she ultimately rejected, officials said.
After lawmakers this year publicly referred to the supposed "internal review," the CIA began to suspect that the committee had obtained those files. U.S. officials said CIA security personnel then checked logs of the computer system it had set up for the panel, and found that the files had been moved to a part of the network off-limits to the CIA.