A Yemen-based Anwar al Awlaki is tipped to succeed al Qaeda chief Osama bin Laden, who was killed earlier this week in Pakistan by US Navy SEALs in a commando strike, a media report said.
US-born cleric al Awlaki is dubbed the bin Laden of internet because he uses the web to spread his evil gospel.
The 40-year-old called for a Mumbai-style massacre during a sting operation carried out by The Sun.
He has already engineered a string of attempted outrages here and in the US, The Sun reported.
Al Awlaki allegedly brainwashed 21-year-old student Roshonara Choudhry into stabbing labour MP Stephen Timms over his support for the war in Iraq. He also allegedly urged British Airways computer worker Rajib Karim, 31 - now in jail - to assist in a plot to blow up an airliner in a Lockerbie-style attack.
He was also allegedly behind last year's ink bomb plot to down cargo jets.
Al Awlaki preaches against vice, but has been arrested twice for using prostitutes - while married, the report says.
The US-born cleric was collared in San Diego in 1996 and 1997. He was fined the first time and put on probation the second.
His radicalisation started in 1993 when he visited Afghanistan during a holiday from Colorado State University, where he studied engineering. On his return, he began advocating holy war. By 1996, he was an imam (cleric) at a mosque with more than 300 followers.
Al Awlaki, believed by US detectives to be "at the centre of the 9/11 story", left the US in 2002. He spent two years in Britain, becoming well-known on the extremist lecture circuit, before heading to his family's native Yemen to continue his increasingly hostile rants.
He linked up with his tribe, whose motto is "We are the sparks of hell."