FORT MEADE, Md. -- An FBI investigation into the legal team representing Sept. 11 mastermind Khalid Sheikh Mohammed further delayed the military trial of him and his co-defendants in Guantanamo Bay on Thursday.

The full nature and scope of the FBI's investigation is not clear. A security contractor working for the defense team, however, did reportedly talk to FBI agents about Mohammed's manifesto, which was published by The Huffington Post in collaboration with Britain's Channel 4 News. The contractor signed an agreement with the FBI after two agents visited his home nearly two weeks ago, which one defense attorney described as an attempt to "introduce a Trojan Horse behind the wall of attorney-client privilege."

Members of the prosecution team, which includes both military officials and civilian lawyers working for the Department of Justice, said they didn't know about the FBI's investigation until last Sunday. They had previously asked the military judge to ask the defense attorneys how the manifesto, which they called "propaganda," got out.

Justice Department lawyer Fernando Campoamor-Sanchez, however, does know the details of the FBI's probe. Campoamor-Sanchez, a lawyer in the U.S. Attorney's Office for the District of Columbia who has worked drug and murder cases and has a top security clearance, was assigned to the prosecution as a special trial counsel late Wednesday.

Campoamor-Sanchez will represent the government going forward as the commission seeks to determine whether the FBI investigation creates a conflict of interest for any of the defense lawyers. The other prosecution lawyers will wall themselves off from the commission's probe into what appears to be an attempt by the FBI to infiltrate the defense teams. KSM defense attorney David Nevin acknowledged to Judge Col. James Pohl in court on Thursday, saying that the FBI's investigation seemed to be aimed at his team.

Campoamor-Sanchez wants to file his response without providing a copy to the defense team, a move that James Connell, the lawyer for co-defendant Ammar al Baluchi, said he will oppose. "The defense is the key player in any investigation into the breach, and the government's effort to stop the defense from learning the facts has the interests exactly backwards," Connell said.

This week was the only pretrial hearing in the 9/11 trial held at Guantanamo in the past four months, and it was originally supposed to focus on the mental competency of Ramzi bin al Shibh, another co-defendant. The next pretrial hearings are scheduled for June, and that week could also be consumed by the inquiry into the FBI probe. Nevin has suggested that he might have to step away from the case if a conflict of interest is found, which would delay the trial for an untold amount of time.

Nearly 13 years after the Sept. 11 attacks, the constant delays in the trial continue to weigh on the families of victims. While the prosecution thinks the trial can go forward in January 2015, Connell said he's not even confident it will start in 2016. "We're nowhere near a trial," he said. Gen. Mark Martins, the chief prosecutor, said he'll see the case out and has taken steps to delay his retirement for at least another three years.

There could be another president in office before the Sept. 11 trial even gets underway, Connell said.

"It is by no means clear that this case will proceed to trial during the Obama Administration," Connell told The Huffington Post in an email.

In a meeting with reporters in Guantanamo on Wednesday while court was in recess, family members of Sept. 11 victims suggested that the Obama administration was trying to "sabotage" the military commission proceedings, possibly in an effort to get the case sent back to federal court. Attorney General Eric Holder originally announced the trial would take place in Manhattan, but the administration backed down from holding it in federal court due to strong political opposition. Holder said late last year that KSM and his co-defendants "would be on death row as we speak" if the case had proceeded in federal court.

"It wasn't just some rogue FBI agent,"Donald Arias, whose brother Adam was killed in the attack on the World Trade Center, said of the investigation.

"This had to be approved at the highest levels within the FBI to do this. They had to know this would have some effect on the proceedings here," he continued. "Were I a very suspicious person, some could even say that was done purposely to derail this hearing and force it back into federal court."