Home Secretary Theresa May has been removed from an official list of British ministers and diplomats who met with a US Senate committee investigating the abuse of terror detainees.
The Foreign Office blamed a "clerical error" for the Cabinet minister being among senior UK figures it said had talked with the panel on 23 occasions since 2009 in response to a request under the Freedom of Information Act.
Details of the meetings intensified questions over whether the Government sought to exclude embarrassing information about alleged British complicity in torture in the Senate Intelligence Committee's damning report.
Downing Street had confirmed the Home Secretary met with the committee and that the encounter would have covered a "wide range of issues" and it was announced that Mrs May would be questioned on the CIA's detention and interrogation programme by the Home Affairs Select Committee on Monday.
In a fresh statement however, the FCO said she was wrongly included.
"Due to a clerical error, which we very much regret, the FCO's FOI response of 1 August on contacts with the US Senate Select Committee on Intelligence, which has been widely reported today, referred to a meeting between the Committee and the Home Secretary in July 2011," it said.
"That was a mistake: her planned visit in July 2011 did not take place and was postponed until September 2011. On that reinstated visit in September 2011, she did not meet the committee."
Former security minister Admiral Lord West, who was also among those listed, said his meeting with the committee in October 2009 was focused on the British cyber security strategy and he "absolutely didn't lobby any committee about this report".
Downing Street has confirmed that British spies spoke to their US counterparts to discuss potential redactions to the damning report on "national security grounds" - after initially suggesting that none had been requested.
A spokeswoman insisted however that: "My understanding is that no redactions were sought to remove any suggestion that there was UK involvement in any illegal torture or rendition.
"There was a conversation between the agencies and their US counterparts on the executive summary. Any redactions there would have been on national security grounds."
Admiral Lord West conceded that there may have been the "odd case" where British agents were aware of torture being carried out by the CIA at a time when it was not clear "exactly what their position was in regards to these things".
But he told the BBC: "T hat is now made very, very clear. It started to be made clear by the last government that they must not be involved at all or even around when this is going on."
Deputy Prime Minister Nick Clegg has acknowledged a full judicial inquiry may still be required into allegations of British complicity in torture if police and parliamentary probes fail to answer key questions.
Tom Davies, Amnesty UK's Stop Torture Campaign manager, said: "The problem is we don't know what we don't know.
"We were told that no redactions were requested which turned out to be completely untrue. Now we're being told anything that was obscured was hidden on grounds of 'national security'. How can we trust that?
"We need to know precisely what was done in our name.
"The British public is tired of being fobbed off with lies, half-truths and inadequate investigations. Nothing short of an independent, judge-led inquiry will draw a line under this shameful chapter.
"At the moment the UK is acting like it's afraid to turn over the rock for fear of what it will find underneath."
Other than Lord West's in October 2009, the meetings were all between the current and former UK ambassadors to Washington and individual members of the committee on separate occasions, the FCO said.
Mr Davies said: "The Government is tangling itself up in its own admissions and denials."
Isabella Sankey, director of policy for rights campaign group Liberty, said: "Torture is torture - it's unjustifiable, no matter how many or how few people knew it was happening.
"Lord West shows a chilling disregard for the most fundamental of democratic values - the rule of law.
"Anyone, anywhere, who was complicit in these crimes must face prosecution but until our Government sets up a transparent, judicial inquiry, cover-up and official impunity will persist."
The Foreign Office said the Home Secretary had been due to meet committee members on the original trip but did not do so after it was rescheduled.