David Petraeus, the scandal-hit former CIA chief, faced a Congressional grilling on Friday over conflicting accounts of the attack in September on the US consulate in Benghazi.

Petraeus, in his first public outing since resigning from the CIA a week ago over an affair with his biographer, was smuggled into Congress for an early-morning hearing to avoid a media scrum.

Appearing before a closed-door hearing of the House intelligence committee, the affair surfaced only once when he was asked if it had had an impact on earlier testimony. He assured the committee it had not.

The rest of the 90-minute hearing was devoted to the various official accounts of the attack on the US consulate in Benghazi on 11 September that left the ambassador, Chris Stevens, and three other Americans dead.

Republicans in Congress have been campaigning relentlessly over discrepancies between the initial explanation provided by theObama administration that blamed the attack on a spontaneous demonstration over a US-produced anti-Muslim film, and a later explanation that blamed al-Qaida elements. They have targeted the US ambassador to the UN, Susan Rice, who gave the first explanation in a round of TV interviews a few days after the incident.

Peter King, the Republican chairman of the committee, said after the hearing he was not satisfied with Petreaus's explanation of how Rice's talking points were compiled. King said: "It is still not clear how the final talking points emerged. He [Petraues] said it went through a long process involving many agencies including the Justice Department and including the State Department.

"No one knows yet who came up with final version of the talking points other than to say the original talking points prepared by CIA were different from the ones that were finally put out."

King saw a contradiction between the account Petraeus had given to an earlier House hearing and the one he gave on Friday.

"His testimony was he told us that from the start it was a terrorist attack. I told him that was not my direct recollection. The clear impression we were given was that the overwhelming amount of evidence was that it arose out of a spontaneous demonstration and [not] that it was a terrorist attack."

Some Republicans have expressed suspicions that Petraeus's resignation had been timed to avoid a scheduled appearance on Thursday before the congressional hearing. Petraeus agreed to appear on Friday instead, even though he is no longer the CIA chief.

King,said that Petraeus did not appear to be disconcerted by the loss of the CIA job and the revelations about the affair. The hearing had been cordial and Petraeus had been professional, knowledgeable and strong but overall it had been awkward.

"I consider him a friend which makes the questioning tough, to be honest with you," King said. "It's a lot easier when you dislike the guy."

Asked if the affair had come up, King said: "Only in answer to one question when he was asked at the start if it had an impact on his testimony and he said 'No'."

A large number of journalists gathered outside the corridor close to the hearing in hopes of snatching an interview with Petraeus, but congressional officials took him through a back entrance. The hearing was held in an extra-secure location several floors below ground level.

© Guardian News and Media 2012