According to the Washington Post "FBI and Justice Department investigators are increasingly frustrated by the silence of jailed suspected associates of Osama bin Laden's al Qaeda network, and some are beginning to that say that traditional civil liberties may have to be cast aside if they are to extract information about the 11 September attacks and terrorist plans".
So far more than 150 people have been detained in the US in connection with the World Trade Centre and Pentagon attacks, although attention has focused on four suspects who, according to the WP, are "held in New York [and] who the FBI believes are withholding valuable information".
So far, FBI agents have attempted to bribe the suspects with the prospect of material gain and lighter sentences - without success. Under US law evidence gained through torture or inhumane treatment is considered inadmissible in court. One solution mooted by an FBI agent would be to extradite suspects to countries where torture is more acceptable.