A US General has thrown out the conviction of the sole US officer charged over the abuse at Baghdad's Abu Ghraib jail, the US Army says.

After a week-long court martial in August, Lieutenant Colonel Steven Jordan, 51, who oversaw the Abu Ghraib interrogations centre from September to December 2003, was acquitted of the most serious charges of mistreating prisoners and dereliction of duty.

He walked free with just a fine and a judicial reprimand for disobeying an order not to discuss the scandal with any colleague.

On Tuesday, however, General Richard Rowe, commanding general of the US Army Military District of Washington, who headed the court martial of Jordan, "disapproved the guilty finding and the sentence," an Army statement said.

"In light of the nature of the offence Jordan had been found guilty of committing and the substantial evidence in mitigation presented at trial and in post-trial matters submitted by defence counsel, Rowe determined that an administrative reprimand was a fair and appropriate disposition of the matter," it added.

An administrative reprimand, unlike a judicial reprimand like Lieutenant Colonel Jordan had previously been given, leaves no written judicial record of the case.

General Rowe's decision effectively closes the book on the Abu Ghraib prison scandal that so outraged the world after photographs of US soldiers abusing Iraqi detainees at the prison outside of Baghdad were published in April 2004.

After several investigations and years of hearings and military trials, only 11 soldiers - those in the photographs - were found guilty and given sentences that ranged from the equivalent of a slap on the wrist (a few hours of community service) to up to 10 years in prison.

A handful of their superiors were reprimanded, and a brigadier general was demoted to colonel.

- AFP