“I do not have any recollection that day of there being a discussion of something that would have been as neon as waterboarding or other torture techniques,” Mr. Graham said.

He said his confidence in the C.I.A.’s account of the briefings had also been shaken by what he said was an incorrect assertion by the agency that he had been briefed on four dates. Mr. Graham, who famously keeps a detailed record of his daily activities, checked and determined that the agency was wrong about three dates and that he had attended only one session before leaving the Intelligence Committee.

“This is just a small chapter of a long, long book of C.I.A. inaccuracies, particularly in the early part of this decade,” he said.

But Mr. Graham was not present for the briefing with Ms. Pelosi. The only other lawmaker present, Porter J. Goss, then a Republican congressman from Florida who was the chairman of the House Intelligence Committee and later became the C.I.A. director, has contradicted her account. He said he and Ms. Pelosi were told that the agency intended to use the harsh methods.

Republicans on Friday continued to dispute Ms. Pelosi’s assertion that at her sole 2002 briefing as a member of the House Intelligence Committee, she was told that the Bush administration had determined waterboarding was legal but that it was not being used.

Senator Christopher S. Bond, Republican of Missouri, a member of the Intelligence Committee, said on the “Today” show on NBC: “I have looked at the underlying materials, not only the records they kept but the cables they sent out to the field. From what was apparently contemporaneous documents, it’s clear that they did tell her.”

The furor surrounding Ms. Pelosi’s claim that she was misled has obscured one undisputed fact about the briefings. The Sept. 4, 2002, session, the first given to anyone in Congress on the so-called enhanced interrogation methods, came weeks after the C.I.A. had started to use the methods. Even if Ms. Pelosi had taken action, it is doubtful it would have averted the firestorm about torture that was to come.