A commanding Army officer is under investigation over allegations that he sexually assaulted subordinates at his unit in Gangwon Province, the Ministry of National Defense said Thursday. The Army took over the case and is looking at whether there were more victims, it added.

“A commander is facing serious charges and we thought it would be more prudent for us to ask our team to pursue the case rather than have the unit run its own probe,” Defense Ministry spokesperson Boo Seung-chan said.

At the same time, the military is expanding its investigation of other sex crime allegations made by an Air Force master sergeant who took her life in May. She said there had been a systemic cover-up and the defense minister agreed, vowing strong punishment for those involved.

The commander at the center of the latest case, a lieutenant colonel who has been relieved of duty, faces arrest on charges of sexually assaulting and harassing at least three female officers -- one commissioned, the other two noncommissioned. One of the officers reported the alleged misconduct to a major general overseeing her unit.

The Defense Ministry also said it was launching a committee comprising civilian experts to advise military prosecutors on their investigation. The panel was put together to boost civilian oversight of the armed forces.

Its launch was prompted by public outrage over the sex crime investigation, whose handling is believed to have led to the suicide of the Air Force master sergeant. It is the first time outside experts will sit on military prosecution teams.

By Choi Si-young (siyoungchoi@heraldcorp.com)