The 25th Marine Regiment’s senior leadership has been fired following an investigation, a Corps official confirmed on Thursday.

Col. Morgan Mann, regimental commanding officer; Sgt Maj. James Boutin, regimental inspector instructor; and CWO 3 Robert Hoy, personnel officer, all were relieved of command Wednesday by Lt. Gen. Rex McMillian, commander of U.S. Marine Corps Forces Reserve, said MARFORRES spokesman Lt. Col. Ted Wong.

McMillian lost confidence in the three Marines’ ability to command, said Wong, who declined to elaborate on why McMillian decided to fire them.

Wong also declined to say what the investigation that led to their dismissal was looking into or whether any allegations against Mann, Boutin or Hoy were substantiated.

Mann became commanding officer of the Fort Devens, Massachusetts-based regiment in March, according to his official biography. He enlisted in the Marine Corps in 1987, and was commissioned as a second lieutenant after completing a Naval Reserve Officers Training Corps scholarship.

The combat veteran deployed twice to Iraq and then to Afghanistan, his biography says. His military awards include the Bronze Star with “V” device for valor, Legion of Merit, Meritorious Service Medal with gold star, Combat Action Ribbon, Navy/Marine Corps Commendation Medal and the Navy/Marine Corps Achievement Medal. He is also a former member of the Marine Corps Reserve Policy Board.