International Red Cross reports on detainees cannot be disclosed to a U.S. military commission trying five detainees accused of the Sept. 11, 2001, terror attacks without the organization’s permission, a Red Cross lawyer told a Guantanamo Bay military judge Tuesday.

Attorneys representing Khalid Sheikh Mohammed and four co-defendants are seeking access to the reports, the only independent assessments of their clients’ conditions during more than a decade in U.S. custody, in a search for evidence they hope will avert the death sentence should their clients be convicted.

The International Committee of the Red Cross visits prisoners captured during armed conflict and provides confidential reports and recommendations to the detaining power to promote compliance with the Geneva Conventions and other humanitarian standards.