Someone else besides the judge and security officer sitting inside the maximum-security court here can impose censorship on what the public can see and hear at the Sept. 11 trial, it was disclosed Monday

The role of an outside censor became clear when the audio turned to white noise during a discussion of a motion about the CIA’s black sites.

Confusion ensued. A military escort advised reporters that the episode was a glitch, a technical error. A few minutes later, the public was once again allowed to listen into the proceedings and Army Col. James Pohl, the judge, made clear that neither he nor his security officer was responsible for the censorship episode.

 “If some external body is turning the commission off based on their own views of what things ought to be, with no reasonable explanation,” the judge announced, “then we are going to have a little meeting about who turns that light on or off.”

 His comments appeared to be aimed at the Pentagon prosecution team. Attorney Joanna Baltes, representing the Justice Department on secrecy matters in the case, advised the judge that she could explain what other forces have a hand in censoring the court proceedings. But not in open session.

 The alleged 9/11 mastermind Khalid Sheik Mohammed and his four accused conspirators were sitting in court, listening to everything that was being said — from the part that the public was forbidden to hear to the judge’s demand for an explanation. Three of the defendants adorned their traditional white tunics with camouflage, an attire option they won from the judge to appear at trial as self-styled soldiers.

The strange censorship episode occurred as attorney David Nevin, defending Mohammed, was advising the judge that defense lawyers had wanted to argue a motion in court to preserve whatever remained of the CIA’s secret overseas prison network. Prosecutors had filed a classified response to the request, and the judge asked the two sides if they would let their motions speak for themselves. Nevin was explaining why not.

 Defense lawyers argue the alleged 9/11 conspirators were tortured in the so-called “black sites,” and that the U.S. government has lost its moral authority to seek their execution. The CIA set up the sites during the Bush administration, reportedly in Poland, Romania, Thailand and elsewhere. President Barack Obama ordered them closed.

 The lawyers want the judge to order the government to preserve what’s left of them, six years after Mohammed and his co-defendants were moved to Guantánamo for trial. This is a familiar role for Pohl, who was the judge in the 2004 trials of U.S. soldiers for detainee abuse at Abu Ghraib and declared the prison in Iraq a crime scene, forbidding its demolition.

 Unclear so far in these hearings is whether the judge knows where the black-site prisons were and whether any of them remain. Although he has a special security clearance to hear the 9/11 case, the CIA has not yet released classified information to the court because the defense and prosecution are still haggling over a protective order.

 But to court observer Phyllis Rodriguez, the judge appeared “furious” and “livid” when he realized that that outsiders had their finger on the censorship switch of his courtroom.

 “It’s a ‘whoa moment’ for the court,” said Human Rights Watch observer Laura Pitter. “Even the judge doesn’t know that someone else has control over the censorship button?”