A US military investigation into a National Guard soldier who is accused of murdering two of his superiors has recommended he be court martialed.

Captain Philip Esposito and Lieutenant Louis E Allen were killed by an explosion in June at an American base near ousted dictator Saddam Hussain's home town of Tikrit.

The military investigation, centered on Staff Sergeant Alberto B Martinez, of Troy, New York State, announced that it had found "reasonable cause" to believe that Martinez had engineered the deaths with an anti-personal mine and three grenades in what investigator Colonel Patrick Reinert said was ‘personal vendetta.'

The court martial recommendation comes after a two-day hearing in a Kuwait military camp.

Martinez' defence team argued there was no real evidence against him.