Testimony put off as judge in 9/11 case at Guantanamo looks into FBI leak probe

In this pool photo of a Pentagon-approved sketch by court artist Janet Hamlin, defendant Ramzi Binalshibh, center, attends his pretrial hearing along with other defendants at the Guantanamo Bay U.S. Naval Base in Cuba, Monday, April 14, 2014. From right to left are Mustafa al Hawsawi, partially cut off, Ali Abdul Aziz Ali, Ramzi Binalshibh, Walid bin Attash and Khalid Sheikh Mohammad. A lawyer for one of five defendants in the Sept. 11 war crimes tribunal said Monday that FBI agents questioned a member of his defense team, apparently in an investigation related to the handling of evidence, a revelation that brought an abrupt halt to proceedings. The disclosure came at the start of what was supposed to be a mental competency hearing for Harrington's client, Ramzi Binalshibh, a Yemeni accused of providing logistical support to the Sept. 11, 2001, terrorist plot. (AP Photo/Janet Hamlin, Pool) (The Associated Press)

An apparent FBI investigation has at least temporarily shut down the effort to try five Guantanamo Bay prisoners by military commission for the Sept. 11 terror attack.

The U.S. government brought about 200 people to the U.S. base in Cuba for a hearing into whether one defendant is mentally competent to stand trial in the death penalty case.

But that plan has been dashed by the revelation that the FBI is investigating how the self-proclaimed mastermind of the attack was able to send two letters and an essay out of the prison without passing through a security review.

The judge began an inquiry Tuesday into the FBI investigation and how it may affect the case over despite a prosecution request to go ahead with the mental competency hearing.