US terror suspect dies in jail

The FBI has detained more than 800 people

By the BBC's Malcolm Brabant in New York

A Pakistani man arrested by the FBI as part of its investigation into the 11 September attacks has been found dead in his cell.

He is thought to have died of a heart attack, but tests for anthrax poisoning have been carried out on his body.

The 55-year-old man was one of more than 800 people detained by the FBI after the attacks on New York and Washington.

The man, whose name has not been released, was found dead in his cell in a county jail in New Jersey.

The post mortem examination is being performed to determine what killed him but medical staff at the prison say he is thought to have suffered a heart attack.

Tests for possible anthrax contamination were performed on the man, his cellmate and a number of guards but according to prison officials the tests were negative.

The FBI, which is being highly secretive about its investigation into the attacks is refusing to say whether the dead man was a significant suspect, but the agency has revealed that it is waiting for the results of anthrax tests taken in the Jersey City apartment of three other detainees.

Khan is one of the prime suspects in custody

It has been reported that articles on bio-terrorism were found inside the flat belonging to Mohammed Pervez, Mohammed Jaweed Azmath and Ayub Ali Khan.

Mr Azmath and Mr Khan are regarded as prime suspects by the FBI - they were arrested on a train in Texas in September allegedly in possession of hair dye, $5,000 in cash and box cutting knives similar to those used by the hijackers.

They were booked on a plane from San Antonio to Denver on 28 September.

Mr Azmath and Mr Khan are reportedly refusing to co-operate with investigations, but US officials believe that their arrest prevented another hijacking.