The US Government reportedly handed over secret information about al-Qaeda to terror suspect Zacarias Moussaoui by accident.

Mr Moussaoui is the first person to be charged in connection with the 11 September terrorist attacks on America.

Documents - both on disk and paper - were given to Mr Moussaoui along with materials to which he was entitled for his legal defence, America's ABC network reports, quoting legal sources including one at the US Justice Department.

Once the discovery was made, federal officers were sent to search Mr Moussaoui's cell to retrieve the material.

The authorities are "still looking into it, just in terms of making sure that we did get everything back", ABC's Justice Department source said.

'20th hijacker'

It is not, however, thought possible that Mr Moussaoui would be able to pass on any information retrieved from the material, as he reportedly is not permitted any communication with the outside world.

Moussaoui faces charges of conspiracy to commit terrorism

The 34-year-old, a French citizen of Moroccan origin, has been in detention since he was arrested last summer after arousing suspicion at a flight school in Minnesota.

He is charged with taking part in planning for the 11 September attacks and is believed by many law enforcement officers to be the "twentieth hijacker" - prevented from carrying out his mission only because he was already under arrest.

Mr Moussaoui has denied involvement in the attacks although he has admitted to being a member of al- Qaeda.

Four of the six conspiracy charges he faces carry a possible death sentence.

His trial is due to start in January. It was postponed by three months due to the "volume and complexity" of the alleged evidence against him.