(CN) - The U.N. Special Rapporteur on Torture claims the U.S. military's extreme secrecy in Pfc. Bradley Manning's case is interfering with the rapporteur's ability to do his job.
Discovery in Manning's court-martial begins Thursday.
Manning, 24, is accused of sending more than 700,000 confidential government files to Wikileaks.
The Pentagon claims he "aided the enemy." Manning's supporters say the military over-classifies documents, and that the leaks blew the whistle on corruption without compromising national security.
In the discovery hearing Thursday, defense attorneys and military prosecutors will try to gain access to documents and witnesses.
Defense attorney David Coombs has long complained that the military barred him from witnesses and files central to his client's defense.
The U.N. Special Rapporteur on Torture and the Reporters Committee for Freedom of the Press have both said that the U.S. government's secrecy is interfering with their ability to do their jobs.
More than 40 news organizations on Monday sent a letter
to Pentagon lawyer Jeh Johnson, claiming the government has granted reporters less access to legal records for the Manning case than for cases involving terrorism suspects in Guantanamo Bay.
"As such, the coalition respectfully urges the government to implement similar reforms in its regulations governing court-martial proceedings generally and that of Manning specifically to ensure that military personnel tried stateside have the same rights to a public trial as those afforded accused terrorists," the letter states.
The letter asked that the Department of Defense hold to the same standards for domestic courts-martial as with military commissions, including prompt online posting of filings, rulings and unofficial transcripts and quick resolution of classification procedures.
In a document dated Feb. 29 but first cited this week, U.N. Special Rapporteur on Torture Juan E. Mendez condemned what he learned about Manning's 11 months of solitary confinement at the Marine Corps Base in Quantico, Va.
In the document
first cited by The Guardian, the newspaper reported that Mendez accused the United States of using "cruel, inhumane and degrading" treatment toward Manning.
In an addendum to his report, Mendez repeatedly expressed frustration that he could not speak to Manning without monitoring.
"The U.S. Government authorized the visit but ascertained that it could not ensure that the conversation would not be monitored," Mendez wrote in the addendum. "Since a non-private conversation with an inmate would violate the terms of reference applied universally in fact-finding by Special Procedures, the Special Rapporteur had to decline the invitation."
Mendez said the U.S. government told him that Manning was in "prevention of harm watch" rather than "solitary confinement," but stonewalled questions about what alleged harms were being prevented.
Manning eventually was transferred to Ft. Leavenworth, Kan., and will appear in Ft. Meade, Md., on Thursday for the discovery hearing.