Seoul, Nov 21 (AHN) The special counsel investigating the 2023 death of a Marine said on Friday it has indicted former President Yoon Suk Yeol on charges of exerting undue pressure on the military's investigation into the case, with 11 other former senior security and defence officials also indicted.

Yoon has been questioned by the special counsel over suspicions that he ordered the presidential office and the defence ministry to reverse the initial findings of a military investigation into the death of Cpl. Chae Su-geun, in order to relieve a then Marine commander of responsibility.

The latest indictment is an addition to other indictments brought against the ousted former leader over his brief imposition of martial law on December 3, Yonhap News Agency reported.

Yoon will stand trial on charges of abuse of power and tampering with official documents.

This indictment comes without physical detention, but Yoon has already been placed under arrest on martial law-related charges.

The special counsel also indicted 11 others, including former spy chief Cho Tae-yong and former Defence Minister Lee Jong-sup, for their alleged involvement in Chae's case at Yoon's instructions.

The Marine died on July 19, 2023, after being swept away in a swollen stream during a search mission for victims of heavy rains without wearing a life vest or other safety equipment.

A military investigation into the case concluded that eight individuals, including Lim Seong-geun, former commander of the Marine Corps 1st Division, were suspected of occupational negligence resulting in death.

Lee, then defence minister, had initially approved the investigation report without objection. But he later ordered the probe not to be referred to the police after Yoon "burst into rage" upon being briefed on its findings, according to the special counsel.

Col. Park Jung-hoon, who had led the Marine Corps' investigation into Chae's death, was dismissed from his position after defying Lee's orders.

The special counsel believes that Yoon made unlawful orders to the defence ministry and the presidential office at the time, going beyond his presidential authority.

"The president as the head of the government has the authority to oversee investigative agencies through the heads of each ministry, but this is of a general and declaratory nature, which should be exercised in accordance with the rule of law and principles of due process," the special counsel said.

"Going beyond this and making specific instructions for a specific case undermines the fairness and independence of investigations, and infringes upon people's basic rights through arbitrary law enforcement that is not permitted," it said.

Lee was appointed by Yoon as the ambassador to Australia in March 2024, raising suspicion that Yoon helped him evade responsibility over the Marine's death case.

Yoon has denied all allegations.