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 director John O. Brennan. (Chip Somodevilla/GETTY IMAGES)

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.

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.