Former prisoners, Yemeni officials and rights lawyers say the United Arab Emirates and allied Yemeni forces are running a network of secret prisons across southern Yemen where hundreds of people detained in the hunt for al-Qaeda militants have disappeared and where torture and abuse are widespread.
Senior American defence officials say US interrogators questioned some detainees. But the Pentagon says Americans were not involved in any abuses.
However, legal experts say American participation could violate the International Convention Against Torture, by which obtaining intelligence that may have been extracted by torture inflicted by another party would constitute complicity.
The UAE, a key US ally, is part of the Saudi-led coalition fighting on the side of the government in Yemen against Shiite rebels while also battling al-Qaeda's branch in the country.
