WASHINGTON, Aug. 20 (Xinhua) -- A U.S. military officer accused of abusing detainees at Iraq's Abu Ghraib prison pleaded not guilty to charges against him on Monday.

    Lieutenant Colonel Steven Jordan faced four counts of charges stemming from the abuse scandal at Abu Ghraib between late 2003 and early 2004, including failure to obey a regulation, cruelty and maltreatment of detainees, and dereliction of duty.

    Earlier in the day, two charges against him were dropped by a military judge in Fort Meade, Maryland, on the outskirts of the nation's capital, after an investigator probing the scandal said that he had forgotten to inform Jordan of his rights as a defendant in an interview in 2004. Both the two charges were based on the statements Jordan made during the interview.

    Jordan was charged after photos showing U.S. soldiers abusing Iraqi detainees at the prison were made public in late April 2004.

    Jordan, 51, the former director of the prison's interrogation center, was the last of 12 U.S. military personnel charged in the Abu Ghraib scandal to be court-martialed. All the 11 others have been convicted of crimes at the jail, and the longest prison term of 10 years was handed down to Charles Graner Jr. in January 2005.

    The trial of Jordan began with jury selection on Monday afternoon.