One of the highest ranking US commanders in Afghanistan has come under scrutiny after US military officials accused him of opposing a probe into poor conditions and the ill-treatment of patients at an Afghan-run US-funded hospital in Kabul.

Lieutenant General William Caldwell was in charge of training Afghan forces when complaints about conditions at Dawood National Military Hospital, including "open vats of blood draining out of soldiers’ wounds, faeces on the floor" and patients suffering with maggots, were brought to his attention.

But, he allegedly obstructed an investigation into the hospital because he was under "enormous pressure to present a positive image of the war effort" during the 2010 US midterm election year.

Al Jazeera's Rosiland Jordan reports from Capitol Hill.