Pre-trial hearings at Guantanamo Bay for accused September 11 plotters Khalid Sheikh Mohammed and Ramzi Binalshibh have been postponed until February.
The first two days of hearings would have been the first open pre-trial hearings since the release of a damning Senate report on CIA torture.
Mohammed, Binalshibh and two others accused in the 2001 attacks had been due to appear on Monday before a military court in Guantanamo Bay.
But both hearings have been put off, a Defense department spokesman says.
The prisoners object to being handled by women on religious grounds, which raised the possibility that they would have had to have been forcibly dragged into court.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
It would have been their first public appearance since the Senate Intelligence Committee released a detailed report on the CIA's use of so-called "enhanced interrogation techniques" on detainees in secret prisons after the 9/11 attacks which killed nearly 3,000 people.
Mohammed, the alleged mastermind, was subjected to "waterboarding," a form of near drowning, 183 times, as well as "rectal rehydration" without medical cause.
Binalshibh underwent harsh interrogations featuring waterboarding, sleep deprivation and stress position for 34 days after his capture. The report said CIA analysts concluded he was not a senior Al-Qaeda member.
The hearings, however, were not about the Senate report but about a potential conflict of interest that arose in July when Binalshibh's lawyer learned that his team's security officer had been questioned by the FBI about their activities.
