Up until now, most of the details of prisoner abuse at Guantanamo Bay have come from the detainees. Now, an American soldier has come forward to corrorborate the existence of treatment that violates the Geneva Conventions.

Erik Saar, an Arabic speaker who was a translator in interrogation sessions, has produced a searing first-hand account of working at Guantánamo. It will prove a damaging blow to a White House still struggling to recover from the abuse scandal at Abu Ghraib jail in Iraq.

In an exclusive interview, Saar told The Observer that prisoners were physically assaulted by 'snatch squads' and subjected to sexual interrogation techniques and that the Geneva Conventions were deliberately ignored by the US military. Saar paints a picture of a base where interrogations of often innocent prisoners have spiralled out of control, doing massive damage to America's image in the Muslim world.

Saar was a Bush supporter in 2000. He says Guantanamo changed his outlook.

Two more links: The allegations by Omar Deghayes that he was blinded in one eye and tortured at Guantanamo, and this report (pdf) by the Center for Constitutional Rights, consisting of the statements of detainees Shafiq Rasul, Asif Iqbal and Rhuhel Ahmed, is a must-read.