Chelsea Manning, the U.S. soldier imprisoned over feeding classified documents to the whistleblowing website WikiLeaks, faced a disciplinary hearing Tuesday over contraband found in her cell. If the charges are upheld, the former intelligence analyst could face indefinite solitary confinement — a potential outcome that has been slammed by supporters of Manning as tantamount to torture.

Manning, who is serving a 35-year sentence for passing sensitive diplomatic cables and military documents to WikiLeaks in 2010, is accused of possession of prohibited property, including a magazine, books and an expired tube of toothpaste; disorderly conduct for sweeping food onto the floor; and ignoring a prison officer’s commands.

Civil rights activists have decried her confinement and recent treatment by officials at the military prison in Fort Leavenworth, Kansas, and have said that the threat of indefinite solitary confinement is inhumane. On Tuesday, supporters of Manning delivered a petition signed by more than 100,000 people to the Army liaison office in Congress, according to groups involved in the campaign.

“During the five years she has been incarcerated Chelsea has had to endure horrific and, at times, plainly unconstitutional conditions of confinement," said Chase Strangio, a lawyer for Manning who works at the American Civil Liberties Union.

David Swanson, a campaign coordinator at civil rights group RootsAction.org, added, “The U.S. military in effect is threatening to torture a young woman for having the wrong toothpaste and magazine.”

Among the reading material taken away from Manning by guards was a novel about transgender issues and a copy of the magazine Vanity Fair with Caitlyn Jenner, the former male decathlete who recently announced her intention to live as a woman.

Manning, who joined military service as a man, changed her name from Bradley to Chelsea. Supporters have long fought for her recognition as a woman in the prison.

Stangio said that the reading material deemed to be contraband were being used by Manning to “educate herself and inform her public and political voice.”

He continued, “During the five years she has been incarcerated, Chelsea has had to endure horrific and, at times, plainly unconstitutional conditions of confinement.

"She now faces the threat of further dehumanization because she allegedly disrespected an officer when requesting an attorney and had in her possession various books and magazines that she used to educate herself and inform her public and political voice."

The U.S. military has said that it is committed to a "fair and equitable process" in regards the Manning case. In comments on Thursday, Army spokeswoman Tatjana Christian said Manning's appearance before a disciplinary board was “a common practice in correctional systems to hold prisoners accountable to facility rules.”

Some military legal experts familiar with the facility expressed skepticism that Manning will be punished with indefinite solitary confinement.

Victor Hansen, a retired Army judge advocate who teaches at the New England School of Law in Boston, said conditions at Fort Leavenworth are less restrictive than for inmates in the federal prison system. Hansen said it is unlikely that prison officials would go after Manning just for having reading material and that there may be more behind the charges.

Solitary confinement is common in civilian prisons, jails and detention centers across the United States, where there are an estimated 80,000 people in solitary confinement on any given day, said Alexis Agathocleous, a deputy legal director at the Center for Constitutional Rights.

Al Jazeera and The Associated Press