Abu Qatada was granted asylum in Britain in 1994

Ministers believe London-based Abu Qatada has close links to the al-Qaeda terror network, and has been "directly involved" in terrorist operations.

The claim was made in evidence put before an appeal by three foreign terror suspects against their detention without charge or trial under the Anti-Terrorism, Crime and Security Act 2001, introduced after the 11 September attacks.

Mr Qatada is also expected to appeal against his detention under the act.

The act says people can be held if they pose a threat to national security or have links to international terrorism but are foreign nationals who cannot be deported.

In a dossier submitted to the Special Immigrations Appeals Commission on behalf of the home secretary, the government singled out Mr Qatada for his "extensive contacts with senior terrorists worldwide".

'Spiritual advice'

The dossier said the Jordanian-born Palestinian, who was granted asylum in Britain in 1994, "has been in direct contact with members and supporters of terrorist cells and networks".

"His preachings are known to be an inspiration for a number of individuals involved in terrorist attacks," it said.

"Eighteen video tapes of Abu Qatada's sermons were found in a Hamburg flat used by three of the men alleged to have hijacked the planes that crashed into the World Trade Centre, including the leader of the group, Mohammed Atta."

The document also said Mr Qatada also gave "spiritual advice and encouragement to those involved in terrorist plots in Strasbourg and Paris".

"The evidence is clear Abu Qatada supports the overthrowing by violent means of some current governments of Arab countries and their replacement with Islamic states," it stated.

Deportation appeal

Mr Qatada preached with the radical cleric Abu Hamza at the Finsbury Park mosque in north London.

The dossier said the two men, as "Islamic extremist spiritual advisors", played "a vitally important role in radicalising young Muslims" and recruiting them for terror training camps.

Terrorists believed their teachings provided the religious "legitimacy" for their attacks, it said.

Earlier this year, the Charity Commission banned Abu Hamza from preaching at the Finsbury Park mosque.

Last month he lodged an appeal to try to stop the government using new laws to strip him of his citizenship and deport him for acting against UK interests.

Government lawyers have also told the hearing the three men appealing against their detention had provided "critical assistance" including equipment and clothing for terrorists.

The hearing was adjourned until Thursday.