A United Nations investigator called the conditions cruel, inhuman and degrading, but stopped short of calling it torture.

Pfc. Bradley Manning is expected to testify about his treatment during a pretrial hearing Tuesday at Fort Meade. The young intelligence analyst has not spoken publicly about his nearly nine months at the Marine Corps brig in Quantico, Va., but he has complained in writing about being confined alone in a 6-by-8-foot cell for at least 23 hours a day. For several days in January 2011, all his clothes were taken from him each night until he was issued a suicide-prevention smock.

The hearing is scheduled to run through Sunday.

Manning is accused of sending hundreds of thousands of classified Iraq and Afghanistan war logs and more than 250,000 diplomatic cables to the secret-spilling website WikiLeaks while he was working as an intelligence analyst in Baghdad in 2009 and 2010.

The 24-year-old native of Crescent, Okla., allegedly told a confidant-turned-informant in an online chat in 2010 that he leaked the information, saying: “I want people to see the truth.”

The Defense Department has said Manning’s treatment at Quantico was proper, given his classification as a maximum-security detainee who posed a risk of injury to himself or others. He was kept at the Marine Corps brig from July 2010 to April 2011, eight months before it was shuttered. He was moved to Fort Leavenworth, Kan., where he was re-evaluated and given a medium-security classification. Army Undersecretary Joseph Westphal said Fort Leavenworth provided an environment “more conducive for a longer detention.”

Publicity about Manning’s treatment helped bring worldwide attention to his case. In March, UN Special Rapporteur on Torture Juan E. Mendez presented a report to the UN’s Human Rights Council, criticizing the U.S. government for refusing his repeated requests for a private visit with Manning.

Although they never spoke, “I am persuaded that Pfc. Manning was subjected to cruel, inhuman and degrading treatment” in violation of the UN Convention Against Torture, Mendez wrote in a Nov. 15 email to The Associated Press.

Mendez said he doesn’t know if Manning’s treatment amounted to torture, as Manning supporters claim.

Military judges can dismiss all charges if pretrial punishment is particularly egregious, but that rarely happens. The usual remedy is credit at sentencing for time served, said Lisa M. Windsor, a retired Army colonel and former Army judge advocate now in private practice in Washington.

“I think the likelihood of him getting any charges dropped is extremely remote,” she said.

In a 2000 case, a military judge denied a motion to dismiss charges against Air Force airman Adrian Fulton, who was forced to perform a strip tease in front of guards and other prisoners, forced to participate in the abuse of other prisoners and threatened with rape and sodomy. Fulton also had to give his pregnant fiancee’s telephone number to a guard who said he planned to have sex with the woman and tell her the airman had become a homosexual, according to court documents. Instead of dismissing the charges, the judge gave the airman 3-for-1 credit for 105 days.

If the military judge refuses to dismiss Manning’s case, defense attorney David Coombs has requested 10-for-1 credit for 258 days of time served. That would knock a little more than seven years off Manning’s sentence if he is convicted. He faces the possibility of life imprisonment if convicted of the most serious charge, aiding the enemy, and 162 years on the 21 other counts. His trial is set to begin Feb. 4.

Jeff Paterson, a leader of the Bradley Manning Support Network, said the credit would be meaningless if Manning gets a lengthy sentence.

“If that credit is meaningless, then that signals that you can actually torture any personnel or detainee without any actual consequences,” Paterson said.

Manning has offered to take responsibility for the leak by pleading guilty to reduced charges. The military judge hasn’t yet ruled on the offer and prosecutors have not said whether they would still pursue the charges against him.