Updated

Lawyers for a Palestinian who has been identified by the Pentagon as one of its "high value detainees" at Guantanamo urged the government Thursday to finally charge the man, saying he deserves a chance to address accusations against him after 10 years in custody.

In a letter to the Convening Authority, a Pentagon legal official who presides over the tribunals known as military commissions at the U.S. base in Cuba, the lawyers for Abu Zubaydah say they have repeatedly sought a "legitimate evaluation" of his case.

"He now requests that the Convening Authority commence prosecution of him before a military commission at the earliest possible date," said the letter signed by four lawyers for the Guantanamo prisoner.

Military commissions have begun for one Guantanamo prisoner charged in the 2000 attack on the USS Cole in Yemen and for five men accused of planning and orchestrating the Sept. 11 attacks whose arraignment was held at the base Saturday.

The chief prosecutor, Army Brig. Gen. Mark Martins, has said the government is reviewing the cases against other prisoners at Guantanamo but has not announced whether any more charges are pending. A Pentagon spokesman, Army Lt. Col. Todd Breasseale, declined to comment on the letter.

Zubaydah was captured in March 2002 and held in a secret network of overseas CIA prisons. He was the first prisoner subjected to the intense interrogation methods that the U.S. has said included 83 instances of the simulated drowning technique known as waterboarding. His lawyers say the treatment amounted to torture.

Joseph Margulies, a lawyer for Zubaydah, says U.S. authorities have since backed off earlier statements that the prisoner was a leader of al-Qaida and senior associate of Osama bin Laden. He says officials now believe he provided logistical support to militants in Pakistan and Afghanistan, but not people affiliated with the terrorist organization.

"We think one of the reasons he hasn't been charged is because of the yawning chasm between who they thought he was when he was the poster child for the torture program and who they now understand him to be," said Margulies, a Professor at Northwestern University School of Law in Chicago.

Since September 2006, Zubaydah has been held with other "high value" prisoners in Camp 7, a top-secret section of the Guantanamo Bay prison, where the U.S. holds a total of 169 men.

Under secrecy rules, his attorneys are not permitted to disclose details about the prisoner or the conditions of his confinement. Magulies said that he has been experiencing gradual memory loss and can no longer remember the names of his parents or his birth date as a result of his treatment in custody.

"We are very concerned about his welfare, about his mental health," he said.