General David Petraeus back in town to give evidence on Benghazi attack

Ousted CIA head appears to contradict earlier testimony that YouTube video was the catalyst

General David Petraeus has claimed that he always believed the US ambassador to Libya was murdered during a "terrorist attack", even though the Obama administration initially described the killing differently.

In closed-doors testimony on Capitol Hill, the ousted head of the CIA reportedly told lawmakers that his agency's draft "talking points" on the 11 September Benghazi tragedy were edited by other security agencies before being shared with the White House.

The claim, made during his first trip to Washington since resigning over an extra-marital affair, will give fresh legs to conspiracy theories already swirling around the death of the Ambassador, Christopher Stevens. It also appears to contradict the evidence that General Petraeus gave at a hearing in September.

Peter King, the Republican chairman of the House Intelligence Committee, said yesterday: "He now clearly believes that [the murder] did not arise out of a demonstration, that it was not spontaneous and it was clear terrorist involvement."

When asked by a reporter if General Petraeus had shed any light on who was responsible for altering the "talking points" used to brief the US public on the attack, Mr King responded that the General "just said it goes through a process, an inter-agency process and when they come back that had been taken out".

Republicans have long accused the Obama administration of attempting to deliberately and wrongly blame the killing of Mr Stevens and three colleagues on a spontaneous backlash against a US-made YouTube video which insulted the Prophet Mohammed.

They believe the alleged cover-up was part of an attempt to prevent negative coverage of the President's foreign policy in the run-up to the election. However General Petraeus does not appear to believe the White House had any role in editing or watering down the "talking points".

"There was an interagency process to draft it, not a political process," said Adam Schiff, a Democrat who attended yesterday's hearing. "They came up with the best assessment without compromising classified information or source or methods. So changes were made to protect classified information.

"The General was adamant there was no politicisation of the process, no White House interference or political agenda," Mr Schiff added. "He completely debunked that idea."

Yesterday's testimony brought a raucous media circus to Capitol Hill. But reporters hoping for a glimpse of General Petraeus were disappointed. He was whisked into the meeting room through a network of underground tunnels that are out of bounds to photographers and TV crews.

He also did not address the scandal that has developed since his resignation last Friday, except to say that the Benghazi attack had nothing to do with his decision to leave.

In a telephone interview on on Thursday General Petraeus told CNN he had chosen to resign from his CIA post because he had engaged in "something dishonourable".