The head of the Senate Intelligence Committee on Tuesday sharply accused the CIA of violating federal law and undermining the constitutional principle of congressional oversight as she detailed publicly for the first time how the agency secretly removed documents from computers used by her panel to investigate a controversial interrogation program. 
 
 Sen. Dianne Feinstein (D-Calif.) said that the situation amounted to an attempted intimidation of congressional investigators, adding: "I am not taking it lightly." 
 
 She confirmed that an internal agency investigation of the action has been referred to the Justice Department for possible criminal prosecution. And she accused the CIA of violating the Fourth Amendment, various federal laws and a presidential executive order that bars the agency from conducting domestic searches and surveillance. 
 
 She has sought an apology and recognition that the CIA search of the committee's computers was inappropriate, but said: "I have received neither." 
 
 Her comments blow wide open a dispute that has simmered behind the scenes in recent weeks after press reports said that the CIA had searched computers intended to be used solely by the panel to in an effort to determine how committee staff members gained access to a draft version of an internal agency review of its controversial interrogation program. The computers were provided by the CIA and housed at a separate facility in Virginia operated by an agency contractors. 
 
 Feinstein confirmed that committee investigators had obtained documents detailing the interrogation policy, but said she didn't know whether they were provided intentionally, unintentionally or by agency whistleblowers. 
 
 "The staff had asked the CIA about documents made available for our investigation. At times, the CIA has simply been unaware that these specific documents were provided to the committee," she said. "And while this is alarming, it is important to know that more than 6.2 million pages of documents have been provided. This is simply a massive amount of records." 
 
 Reading from a prepared text throughout her remarks, Feinstein said she was speaking out "reluctantly" but that she wanted to speak in order to clarify the situation. "The increasing amount of inaccurate information circulating now cannot be allowed to stand unanswered," she said. 
 
 After she spoke, Sen. Patrick J. Leahy (D-Vt.) said, "In 40 years here, it was one of the best speeches I'd ever heard and one of the most important." 
 
 And Senate Majority Leader Harry M. Reid (D-Nev.) credited Feinstein for speaking out and defending the separation of powers. "There is no one who has more courage and conviction than Dianne Feinstein," he said. ||||| Breaking News Emails Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings. 
 
 CIA Director John Brennan told NBC News' Andrea Mitchell that the agency did not snoop on Senate Intelligence Committee computers to thwart an investigation into illegal detention and interrogations under President George W. Bush. 
 
 "We weren't trying to block anything," Brennan said. "The matter is being dealt with in an appropriate way, being looked at by the right authorities, and the facts will come out," he added. 
 
 "But let me assure you the CIA was in no way spying on [the committee] or the Senate." 
 
 The exclusive Tuesday interview was Brennan's first since the head of the Senate Intelligence Committee charged that the CIA had searched the panel's computers, possibly violating the law. 
 
 "The CIA just went and searched the committee's computers," California Democrat Sen. Dianne Feinstein said in a lengthy speech on the Senate floor, calling the the matter a "defining moment" for the oversight of the Intelligence Committee. 
 
 "I have grave concerns that the CIA's search may well have violated the separation of powers principles embodied by the United States Constitution, including the speech and debate clause," she said. 
 
 "It may have undermined the Constitutional framework essential to effective congressional oversight of intelligence activity or any other government function." 
 
 Feinstein added that the search may also have violated the Fourth Amendment of the Constitution, the Computer Fraud and Abuse Act and an executive order that prohibits the CIA from conducting domestic searches or surveillance. 
 
 She said she has asked for an apology and an acknowledgment that the CIA's actions were wrong but that "I have received neither." 
 
 The Intelligence Committee is investigating CIA detention and interrogation practices that date back to when Brennan was directing that program. 
 
 WATCH: Sen. Dianne Feinstein accuses CIA of spying on Intelligence Commitee 
 
 Asked about Feinstein's allegations, White House Press Secretary Jay Carney would not comment on whether the CIA broke any laws but said that "the president has great confidence in John Brennan, and confidence in our inteligence community and in our professionals at the CIA." 
 
 Brennan said that he had not seen Feinstein's speech but was aware of "all sorts of claims out there" that the CIA was meddling in the Senate investigation. 
 
 "That is not the case at all," he said. 
 
 "We greatly respect the separation of powers between the executive branch and the legislative branch," he added. 
 
 Feinstein said the CIA's inspector general turned the matter over to the Justice Department, but Sen. John McCain said an independent probe may be necessary. 
 
 After the interview, in a discussion with the Council on Foreign Relations, Brennan said that he supported any effort to ferret out wrongdoing with respect to commitee computers. 
 
 "I will be the first one to say we need to get to the bottom of it," he said. "And if I did something wrong, I will go to the president and I will explain to him exactly what I did and what the findings were. And he is the one who can ask me to stay or to go." ||||| Correction: An earlier version of this story incorrectly stated there were 10 CIA employees involved in the search of the Senate Intelligence Committee’s computers. There were five. 
 
 CIA employees improperly searched computers used by Senate investigators involved in a multi-year probe of the agency’s use of harsh interrogation measures on terrorism suspects, according to the findings of an internal agency inquiry that prompted CIA Director John Brennan to apologize to lawmakers this week. 
 
 Five agency employees — two lawyers and three computer specialists — surreptitiously searched Senate Intelligence Committee files and reviewed some committee staff members’ e-mail on computers that were supposed to be exclusively for congressional investigators, according to a summary of the CIA inspector general’s report, released Thursday. 
 
 The document criticizes members of the computer team for a “lack of candor about their activities” when they were questioned by investigators working for CIA Inspector General David Buckley. 
 
 The investigation stems from a dispute that erupted in public earlier this year when the CIA and the Intelligence Committee traded accusations of illicit spying and security breaches — allegations that led to an extraordinary feud between Brennan and the Senate panel, which oversees his agency. 
 
 Brennan’s embarrassing apology comes as the CIA is bracing for the long-awaited release of a committee report that is said to be sharply critical of the agency, finding that it exaggerated the effectiveness of interrogation measures and repeatedly misled members of Congress and the executive branch. The report is expected to be released within weeks. 
 
 President Obama said on Friday the CIA "tortured some folks" after the Sept. 11, 2001 attacks. He also said he has full confidence in CIA Director John Brennan despite a revelation the agency spied on a U.S. Senate committee investigating its interrogation techniques. (Reuters) 
 
 In a statement, the CIA said its employees had “acted in a manner inconsistent with the common understanding reached” between the agency and lawmakers in 2009, when the committee’s investigation began. The CIA acknowledgment was first reported by the McClatchy news service. 
 
 After briefing committee leaders, Brennan “apologized to them for such actions by CIA officers as described in the [inspector general’s] report,” the agency’s statement said. Brennan also ordered the creation of an internal personnel board, led by former senator Evan Bayh (D-Ind.), to review the agency employees’ conduct and determine “potential disciplinary measures.” 
 
 Members of the Senate Intelligence Committee expressed vindication, but some made it clear that their animosity toward Brennan persists. Sen. Mark Udall (D-Colo.) called for Brennan’s resignation. He said he had “lost confidence” in the director, citing “the unprecedented hacking of congressional staff computers,” damaging leaks about the committee’s interrogation probe and Brennan’s “abject failure to acknowledge any wrongdoing by the agency.” 
 
 In an interview, Sen. Martin Heinrich (D-N.M.) said, “I think it would be better for the agency if Director Brennan stepped aside.” 
 
 White House press secretary Josh Earnest said President Obama supports Brennan and disputed the idea that the CIA director’s reversal on the clash with Congress had damaged his credibility. “Not at all,” Earnest said, noting that Brennan had initiated the inspector general’s review. 
 
 “He currently is operating in a very difficult environment to ensure the safety of the American public,” Earnest said. “He is somebody who has a very difficult job, who does that job extraordinarily well.” 
 
 Brennan’s apology to lawmakers was in sharp contrast to the defiant position he took when the dispute surfaced publicly in March. At the time, he warned that lawmakers would regret accusing the agency of wrongdoing. 
 
 “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,” he said. 
 
 Brennan was responding to accusations from Intelligence Committee Chairman Dianne Feinstein (D-Calif.) and others that the CIA had secretly removed documents from committee computers and attempted to intimidate investigators by requesting an FBI inquiry of their conduct. 
 
 Feinstein described the conflict as a “defining moment” for congressional oversight of spy agencies and cited concerns that the CIA had “violated the separation-of-powers principles embodied in the United States Constitution.” 
 
 On Thursday, Feinstein said she had been briefed by Buckley. She described Brennan’s apology and decision to convene a personnel board as “positive first steps” and added: “This IG report corrects the record.” Buckley is a former congressional aide. 
 
 As the standoff between the CIA and the committee intensified, Robert Eatinger, a senior lawyer for the agency, issued a referral to the Justice Department asking for an investigation of whether committee staff members had committed a crime by extracting sensitive documents that the CIA hadn’t agreed to turn over. 
 
 The Justice Department closed that inquiry on July 9 after finding insufficient evidence that either side had committed a crime, according to the summary of the inspector general’s findings. But it also appeared to call attention to another agency misstep. 
 
 The allegations that the CIA called to the attention of the Justice Department were “not supported,” Buckley said, “as the author of the referral had been provided inaccurate information on which the letter was based.” 
 
 Eatinger, a longtime agency lawyer who was involved in legal issues surrounding the interrogation program, is mentioned by name in the Senate committee’s report hundreds of times, said officials familiar with the document. 
 
 The agency declined to identify the five employees cited in the inspector general’s report but noted that Brennan was not accused of any wrongdoing. The search of the committee’s computers was carried out by the CIA’s Office of Security. 
 
 The inspector general’s summary noted that its investigation was limited to the conduct of agency officers and not that of congressional staff members. The Senate’s sergeant-at-arms is conducting a separate review. 
 
 Adam Goldman contributed to this report.
– CIA Director John Brennan is hitting back after Sen. Dianne Feinstein confirmed reports that the CIA illegally searched Senate Intelligence Committee computers. "We weren't trying to block anything," Brennan tells NBC. "The CIA was in no way spying on [the committee] or the Senate." Feinstein had earlier equated the surveillance with intimidation, notes the Washington Post, saying, "I am not taking it lightly." The CIA has broken federal laws, an executive order against domestic spying, and the Fourth Amendment, she says. The agency's own probe of the claims has been referred to the Justice Department, and criminal prosecution could be on the table, Feinstein notes. The searching occurred in January, the senator says, per the AP. Her claims come after reports that the CIA spied on computers it had provided to the committee for use in reviewing a trove of millions of top secret documents. The committee was looking into information on interrogation techniques. Further reports suggested that Senate staffers took classified documents from the computers. Feinstein, for her part, says she doesn't know how certain interrogation documents ended up in committee hands—whether they were offered by the CIA, mistakenly provided, or handed over by whistleblowers. Sen. Patrick Leahy called Feinstein's speech "one of the best" he'd "ever heard" on the Hill, "and one of the most important."