A Marine Corps team that investigated the death of a Marine during last month's monsoon search, led by the now-dismissed Col. Park Jung-hun, had reportedly alleged professional negligence on the part of a division commander.

According to Park's legal counsel on Sunday, his client alleged such charges against Lim Seong-geun, the commander of the Marine Corps' First Division, after he allegedly did not internally notify others about the search operation for sufficient preparation.

A group of Marines were dispatched to a rain-damaged region in Yecheon, North Gyeongsang Province, without safety equipment, such as life jackets, from July 15 to 16. Lim only notified a brigade commander about the duty on July 17, which was delivered to unit commanders by that night.

Unit executive officials, who had initially understood that the operation would focus on recovery, had only prepared shovels.

Despite observing the search efforts in the water on the morning of July 18, Lim allegedly failed to direct safety measures, which was followed by the late Lance Corporal Chae Su-geun being swept away in a torrent and later found dead.

Park, who had handed over the probe findings to the police against internal orders, has since been dismissed from his post and booked on charges of insubordination.