London, Feb 21: Sayyid Imam al-Sharif, one of al Qaeda's founders in 1998 and a leading jihadist ideologue who functions under the pen-name `Dr Fadl', has launched a fierce attack on the ideology and personal failings of Osama bin Laden, and particularly his Egyptian deputy, Ayman al-Zawahiri.

Sayyid Imam al-Sharif, who also led an Islamist insurgency in Egypt in the 1990s, has attacked the terror outfit in his book written from inside a Egyptian prison.

Dr Fadl became al-Qaeda's intellectual figurehead 20 years ago with a crucial book setting out the rationale for global jihad against the West, The Telegraph reported.

Today, however, he believes the murder of innocent people is both contrary to Islam and a strategic error.

"Every drop of blood that was shed or is being shed in Afghanistan and Iraq is the responsibility of bin Laden and Zawahiri and their followers," writes Dr Fadl.

The terrorist attacks on September 11 were both immoral and counterproductive, he writes.

Dr Fadl focuses his attack in particular on Zawahiri whom he has known for 40 years. Zawahiri is a "liar" who was paid by Sudan's intelligence service to organise terrorist attacks in Egypt in the 1990s, he writes.

Fouad Allam, who spent 26 years in the State Security Directorate, Egypt's equivalent of MI5, said that Dr Fadl's assault on al-Qaeda's core leaders had been very effective, both in prison and outside.

Dr Fadl was a central figure from the very outset of Osama's campaign and was part of the tight circle, which founded al-Qaeda in 1988 in the closing stages of the war against the Soviet occupation of Afghanistan. (ANI)