|Defence lawyers say the witness was only revealed after intense interrogation of the accused [Getty Images]
The first civilian trial for a Guantanamo Bay detainee has been delayed after a judge told prosecutors they cannot call their star witness.
Lewis A Kaplan, the US district judge, blocked the government on Wednesday from calling a man who authorities said, sold explosives to Ahmed Khalfan Ghailani, the defendant.
Defence lawyers say investigators only learned about the witness after Ghailani underwent harsh interrogation at a secret CIA-run camp overseas between 2004 and 2006.
"The court has not reached this conclusion lightly," Kaplan wrote. "It is acutely aware of the perilous nature of the world in which we live. But the constitution is the rock upon which our nation rests. We must follow it not when it is convenient, but when fear and danger beckon in a different direction."
The government immediately asked for a delay of the trial, which had been expected to begin with opening statements on Wednesday, so that it has time to appeal the ruling, should it decide to do so.
The judge sent a pool of 66 jurors home until Tuesday, but not before warning them to avoid following the case on the news or discussing it with anyone.
Ghailani is charged with conspiring in the 1998 bombings of two US embassies in Africa.
The attacks killed 224 people, including a dozen Americans.
The judge issued his written three-page ruling after a hearing three weeks ago in which Hussein Abebe, the witness, testified about his dealings with authorities.
"The government has failed to prove that Abebe's testimony is sufficiently attenuated from Ghailani's coerced statements to permit its receipt in evidence," Kaplan wrote.
The defence had asked the judge to exclude Abebe's testimony on the grounds that it would be the product of statements made by Ghailani to the CIA under duress.
On that point, Kaplan said, "Abebe was identified and located as a close and direct result of statements made by Ghailani while he was held by the CIA. The government has elected not to litigate the details of Ghailani's treatment while in CIA custody. It has sought to make this unnecessary by asking the court to assume in deciding this motion that everything Ghailani said while in CIA custody was coerced."
The judge noted that he had previously rejected defence motions to dismiss the indictment on the grounds that Ghailani was deprived of a speedy trial and that his treatment by the CIA was so outrageous as to require termination of the charges.