In her 45-minute speech, Ms. Feinstein gave the fullest public account of the years of back-room jousting between her committee and the C.I.A. over the agency’s detention program, and its use of secret prisons and brutal interrogation techniques like waterboarding that critics described as torture.

The dispute came to a head in mid-January when Mr. Brennan told members of the committee that the agency had carried out a search of computers used by committee investigators at a C.I.A. facility in Northern Virginia, where the committee was examining documents the agency had made available for its report.

Ms. Feinstein said on Tuesday that during the meeting, Mr. Brennan told her that the C.I.A. had searched a “walled-off committee network drive containing the committee’s own internal work product and communications” and that he was going to “order further forensic evidence of the committee network to learn more about activities of the committee’s oversight staff.”

The C.I.A. had carried out the search to determine whether committee investigators may have gained unauthorized access to the internal review of the detention program that the agency had carried out without informing the committee. Ms. Feinstein on Tuesday vigorously disputed this allegation, saying the document had been included — intentionally or not — as part of a dump of millions of pages the C.I.A. had provided for the Intelligence Committee.

Mr. Brennan, in a January letter to Ms. Feinstein that a government official who did not want to be identified released on Tuesday, said the committee had not been entitled to the internal review because it contained “sensitive, deliberative, pre-decisional C.I.A. material”— and therefore was protected under executive privilege considerations.

The letter, attached to a statement that Mr. Brennan issued to the agency’s employees on Tuesday, raised questions about Ms. Feinstein’s statements earlier in the day concerning at what point the committee came into possession of the internal review.

The C.I.A.’s acting general counsel has referred the matter to the Justice Department as a possible criminal offense, a move Ms. Feinstein called a strong-arm tactic by someone with a conflict of interest in the case. She said that that official had previously been a lawyer in the C.I.A.’s Counterterrorism Center — the section of the spy agency that was running the detention and interrogation program — and that his name is mentioned more than 1,600 times in the committee’s report.