Washington (CNN) -- Fourteen months after the Fort Hood, Texas, massacre, a Senate panel is still consulting with the FBI over the public release of what the government knew in advance about the accused gunman.
On Tuesday, the Senate Committee on Homeland Security and Governmental Affairs abruptly delayed a hearing that had been set for Thursday. The committee was expected to reveal previously secret details about what government intelligence agencies knew about Army psychiatrist Maj. Nidal Hasan and his contact with Muslim radicals overseas.
Hasan is charged with killing 13 people and wounding 32 at a medical center at Fort Hood in November 2009.
Leslie Phillips, spokeswoman for the Senate committee, confirmed the delay on Wednesday.
"The delay involves negotiations with the FBI over declassification of the report," Phillips told CNN. She provided no further explanation and would not say when the hearing might be rescheduled.
The committee had billed its now-postponed hearing as "A Ticking Time Bomb: Counterterrorism Lessons from the U.S. Government's Failure to Prevent the Fort Hood Attack."
An FBI spokesman confirmed the bureau is still working with the committee on what material can be declassified. He did not offer an estimate how quickly matters could be resolved.
The Senate-FBI standoff has been brewing for more than a year.
The committee began seeking information from the Justice Department within days of the Fort Hood attack, writing U.S. Attorney General Eric Holder and asking him for information.
The committee chairman, Sen. Joseph Lieberman, I-Connecticut, and the ranking Republican, Sen. Susan Collins of Maine, wrote to Holder on November 13, 2009:
"The committee is concerned that there appear to have been significant warnings of Major Nidal Malik Hasan's growing extremist views and suitability for military service that may have been missed, including because they were not adequately shared across agency lines."
The committee also asked the White House and the Department of Defense for information.
Hasan's defense attorney, John Galligan, also has been seeking release of government information about Hasan, both from intelligence agencies as well as Hasan's commanding officers in the Army. Galligan has said he can't prepare a defense of Hasan without that material.
A team of mental health experts delivered its report Friday on Hasan's competency to stand trial and his state of mind at the time of the shooting. The findings of that report are secret, but Galligan has told CNN he doesn't think the report will stop the Army from moving forward with the case.
A senior Army officer now will study the report and decide whether Hasan will face a court-martial with a possible death penalty.
CNN's Carol Cratty contributed to this report.