Amnesty International says a significant number of people detained in the US in the aftermath of the 11 September terrorist attacks continue to be deprived of their basic rights under international law.
A 40-page report based on jail visits and interviews with attorneys, detainees and relatives says many of those held have been arbitrarily detained and subjected to prolonged solitary confinement and heavy shackling.
"These detentions have been surrounded by extreme secrecy, which creates the potential for abuse,
said a spokesman for Amnesty International.
"Our report confirms that basic human rights have been violated, including the right to humane treatment, to be informed of the reasons for the detention, to have prompt access to a lawyer and to be presumed innocent until proven otherwise."
In one case, Rabid Haddad, a Lebanese national charged with overstaying his tourist visa, has been held in solitary confinement since 14 December.