CIA records show Democratic House of Representatives speaker Nancy Pelosi was briefed in September 2002 on harsh interrogation techniques being used on terrorist suspects, but the records do little to settle a dispute over whether she knew waterboarding had already been used against a prisoner by then.
The release in April of once-classified details about harsh Bush-era interrogation techniques, which President Barack Obama last week called "torture", has caused recriminations among congressional and Bush administration leaders who knew about the programme.
Pelosi waded into that debate when she told reporters in April this year that in 2002 she had been briefed on the authorised techniques but was not told that waterboarding had already been used on a prisoner. Waterboarding, which simulates drowning, is the most severe of the 10 techniques approved by the Bush White House. There is no record that Pelosi objected to the use of the techniques.
The CIA on Wednesday sent the House and Senate intelligence committees a chart describing the 40 congressional briefings at which the interrogation programme was discussed, describing who was briefed, on what date and on what subjects.
Pelosi is mentioned only in the first briefing, on 4 September 2002. The chart, drawn from the CIA briefers' memories and meeting notes, says the meeting described the interrogation techniques that had been used on alleged terrorist Abu Zubaydah.
But the CIA chart does not specifically mention the use of waterboarding at that briefing.
According to legal memos released in April Zubaydah was the first of three prisoners to be waterboarded. He underwent the procedure at least 83 times in August 2002.
The first mention of waterboarding comes in the description of a February 2003 meeting attended by Pelosi's successor on the House intelligence committee, California Democrat Jane Harman. Harman wrote to the CIA expressing concern about the techniques, the only known objection formally raised by a member of Congress at that time.
The CIA specifically discussed waterboarding in 13 of the congressional briefings, according to the charts.
Pelosi's spokesman, Brendan Daly, said Pelosi stands by her recollection of the meeting.
"As this document shows, the speaker was briefed only once, in September 2002," said Daly. "The briefers described these techniques, said they were legal, but said that waterboarding had not yet been used."
Even the CIA suggests that its account of the meetings will not settle the debate over who knew what and when.
"In the end, you and the committee will have to determine whether this information is an accurate summary of what actually happened," states the 6 May covering letter from CIA director Leon Panetta to US representative Silvestre Reyes, Democratic chairman of the House intelligence committee.
Representative Pete Hoekstra, the top Republican on that committee, said today that calls for truth commissions or prosecutions for those who approved or carried out harsh interrogations ignore that Congress was fully informed about the methods.
"I think that nobody wants to take any accountability for it," Hoekstra said. "Is it fair to go after people in the CIA or at the Justice Department when Congress was briefed on this programme and knew it was going on? That doesn't seem very fair to me. If there is going to be any accountability, [Congress] is where it needs to start."