Libya's new government headed by Prime Minister Dr Ali Zidan, a former human rights activist, that was sworn in on November 14, 2012, should put the illegal detention of more than 8,000 people atop its agenda, Human Rights Watch, HRW says.
About 4,000 detainees are in government custody, most without formal charges or access to a lawyer, and the rest are held outside government control by various armed groups who have no legal authority to detain anyone, according to HRW.
Eric Goldstein, deputy Middle East and North Africa director at Human Rights Watch said: "The new government can start on the right foot by addressing the detainee crisis."
Mr Goldstein added: "It has an opportunity and an obligation to review thousands of cases with a newfound respect for justice and the rule of law."
Libya's Prime Minister has spoken publicly about the need for reconciliation and the rule of law, while the new justice minister, Salah Marghani, is a longtime human rights lawyer.
Human Rights Watch said that addressing the detainee crisis will require political will and a coordinated effort by the Justice, Interior and Defence Ministries, as well as the General Prosecutor's Office.
Human Rights Watch said that Dr Zidan had told it that his government is guided by human rights principles and he will confront illegal activities by armed groups, including arbitrary detentions and extrajudicial killings.
"I take full responsibility for the safety and security of all Libyans equally, including those who sided with the former regime and their families," he said. "The rule of law must be our source of justice. Human rights is a priority for this newly elected government."
HRW said that the new government should support those claims by bringing all detainees in its custody promptly before a judge and giving them access to a lawyer. If there is sufficient evidence, the person should be charged with a criminal offence. If not, the person should be released, it adds.
Armed groups, who have no legal authority to detain, should be required to hand over all their detainees to state authorities or release them, Human Rights Watch said. Armed groups who refuse to do so and continue to detain people unlawfully should be investigated and prosecuted for unlawful deprivation of liberty.
The precise number of detainees in government and militia custody remains unclear. However, HRW said that the Justice Ministry is holding at least 3,000 people. An estimated 3,000 detainees are being held by a multitude of armed groups.
It goes on to say that another 2,000 people are being held by either the Defence Ministry or the Supreme Security Committee, which it describes as a quasi-official body of former anti-Gaddafi fighters that is cooperating with the Interior Ministry.