On Monday the United States military sent 11 long-term detainees from the facility to Oman after reaching agreement with the Government there on relocation and resettlement.

Only 15 detainees now remain, according to news reports. The prison opened in 2002 and at its peak it held more than 600 prisoners overseen by over 2,000 military and civilian personnel.

Captured in Pakistan

Captured in March 2002 in Faisalabad, Pakistan, following the 11 September 2001 attacks, Abu Zubaydah was transferred to CIA custody and held at multiple secret locations, where he was reportedly tortured, the experts reminded in a press release issued on Wednesday.

Despite being imprisoned for nearly two decades, he remains in Guantánamo Bay without any formal charges having been made.

Release ‘long overdue’

“We are exceptionally requesting a Presidential pardon for Mr. Abu Zubaydah, owing to his treatment while in detention and the lack of due process since he was first detained,” the experts stated. “His immediate release and relocation to a third safe country are long overdue.”

The Human Rights Council-appointed experts highlighted Abu Zubaydah's serious health conditions, which include injuries sustained during torture that have allegedly been exacerbated by the denial of medical attention.

They also noted significant impediments to lawyer-client communication.

Various international and regional human rights mechanisms have examined Abu Zubaydah's case, establishing that he has suffered multiple human rights violations within the context of the US rendition and secret detention programme, the experts noted.

“In addition to his liberation, we request that Mr. Abu Zubaydah is accorded an enforceable right to compensation and other measures of reparation, in accordance with international law,” the working group members and Special Rapporteurs said.

The experts emphasised the profound psychological and physical trauma he has endured due to torture, cruel, inhuman, and degrading treatment, and enforced disappearance. They reiterated their call for the US Government to immediately release and relocate him to a safe third country.

“We recall the principle of joint responsibility that applies to States when more than one of them was involved in the perpetration of a human rights violation,” the experts said. “Accordingly, we call on States to proactively offer their territory for the prompt relocation of Mr. Abu Zubaydah.”

The experts also expressed concerns about the continued detention of 14 other individuals at Guantánamo Bay, who are in varying stages of legal proceedings and face allegations of ongoing human rights abuses.

Independent rights experts are not UN staff, receive no salary for their work and are independent of any organisation or government.