Legal offices that are so contaminated with mold and rat droppings that lawyers in the Sept. 11 terrorism trial have been getting sick will get a full clean-up and be evaluated by safety experts, a military official said Thursday.

A "comprehensive" cleaning of the offices, which are primarily used by defense teams in the Guantanamo Bay tribunals, will begin by the end of the month and be finished in time for a hearing scheduled in December, said Army Capt. Michael Lebowitz, one of the prosecutors in the case of five prisoners charged in the Sept. 11 attacks.

"It's almost like a fresh start," Lebowitz told the case judge, who has been fielding complaints about the offices this week while presiding over a pretrial hearing at the U.S. base in Cuba.

The issue of the contaminated offices has repeatedly interrupted progress on more than two dozen pretrial motions this week. Defense lawyers had sought to postpone the hearing outright, which would have further delayed a case that has been plagued by delays.

A base official declared the offices unsafe in September because of mold and other problems, then the space was declared safe several weeks later after a cleaning. But lawyers distributed photos this week showing the walls and air conditioning units coated with mildew and mold as well as floors littered with what appear to be mouse and rat droppings. Pictures also showed a dead crab and lizard, both common at the tropical base on the Caribbean Sea.

It is more than just aesthetics, lawyers said. Since late 2011, several members of the Sept. 11 defense team have suffered from fatigue and respiratory and eye ailments after trips to Guantanamo Bay.

"Each time I travel to Guantanamo Bay I suffer from increased respiratory and eye problems that have landed me in the Guantanamo emergency room," said Cheryl Bormann, a lawyer for Walid Bin Attash, who is one of the five men charged with planning and aiding the worst terrorist attack on U.S. soil.

Legal office space, which must meet security requirements because the attorneys and their staff handle classified evidence, is in short supply at Guantanamo. The defense teams were forced to cram into a much smaller work space while preparing for the weeklong hearing, which has dealt largely with disputes over the rules for gathering evidence in a trial that is likely more than a year away.

Bormann told the judge she welcomed the military's proposal for a major clean-up and an evaluation by outside health experts. "We want it fixed and we want it fixed right," she said.

The judge, Army Col. James Pohl, had appeared to grow frustrated at the continuing complaints and welcomed a step that he hoped would resolve the issue. "Obviously, if it doesn't, I'll hear," he said.

Among the five men facing charges that include terrorism and murder is Khalid Sheikh Mohammed, who has previously told authorities that he was the mastermind of the Sept. 11 attacks.

Mohammed, who delivered a five-minute lecture Wednesday denouncing the U.S. for killing "millions" in the name of national security, stayed silent during Thursday's court session.

The judge heard arguments on defense motions to change rules for gathering evidence and calling witnesses that defense lawyers said will make it impossible to fairly defend their clients, who could get the death penalty if convicted. Among their complaints is that the rules would prevent defendants from seeing some of the classified evidence against them.

"This is a capital case. His life is literally at stake in it," said David Nevin, the lawyer for the lead defendant. "Mr. Mohammed should be able to see everything."

The defense and prosecution also sparred over the question of the extent to which the U.S. Constitution applies to the prisoners charged in special tribunals for wartime offenses.

The Supreme Court has ruled that the base in Cuba, because it is under U.S. control, is generally covered by the Constitution except when circumstances are deemed "impracticable and anomalous" and cannot be enforced.

The defense has asked the judge to issue an advisory opinion setting out to what extent the Constitution applies to the proceedings since some of their challenges will raise constitutional issues. The prosecution said it is too early to make such a finding.

Pohl did not rule on the issue and the hearing was to continue Friday.