The detainee who died over the weekend was Adman Farhan Abd al-Latif, in his 30s, held since January 2002 as prisoner No. 156, his attorney disclosed Tuesday.

Latif was found unconscious in his cell Saturday afternoon, the military said. Guards and military medical staff could not revive him. He was the ninth detainee to die in the 11 years of the detention center’s history.

The military withheld Latif’s identity while the Naval Criminal Intelligence Service began an investigation and the Obama administration notified members of Congress and Latif’s family of the death. Attorney David Remes said he reached Latif’s brother in Yemen by midday Tuesday, to pass the word.

Latif was not one of Guantanamo’s best known captives. He had never been charged with a war crime, and he was cast at best as an al-Qaida foot soldier in military intelligence assessments obtained by McClatchy Newspapers from WikiLeaks.

For years, Remes has described Latif’s despair in excruciating detail in a bid to draw attention to the case. In December 2010, the lawyer sent reporters by email a translation of a letter from Latif that included: “This prison is a piece of hell that kills everything, the spirit, the body and kicks away all the symptoms of health from them.”

Latif was frequently confined to the prison camps’ mental health ward, Remes reported starting in 2010, a hunger striker who repeatedly tried to kill or harm himself by swallowing shards of metal, trying to eat glass and other foreign objects. He would smear excrement on himself, throw blood at the lawyer, and on at least one occasion was brought to meet his lawyer clad only in a padded green garment called a “suicide smock” held together by Velcro.