Detainees being held by the US military at Guantanamo Bay in Cuba should have access to lawyers and the US court system, a federal appeals court has ruled.
The court said their detention was contrary to US ideals.
It did not accept that the US Government had "unchecked authority".
The ruling relates to the case of a Libyan national captured in Afghanistan and currently being held at Guantanamo.
About 660 people are currently being held as "enemy combatants" at the base.