Former Defense Minister Lee Jong-sup had multiple phone calls with President Yoon Suk Yeol on the day that an internal investigation over a marine corporal's death was transferred to and returned from civilian police in August last year, communication records show.

Yoon called Lee directly three times on Aug. 2 between 12 p.m. and 1 p.m. soon after the internal report by a Marine investigator was sent to the police in the morning, according to the records obtained by Yonhap News Agency.

The report was retrieved from the police later in the evening.

The Marine investigator, Col. Park Jung-hun, was indicted on charges of insubordination and defamation two months later as he handed over the probe findings regarding Cpl. Chae Su-geun's death to the civilian police.

The then-defense minister, Lee, had ordered the Marine Corps' top commander to retrieve the internal probe findings, citing the need for further legal review of the case.

Lee had several phone calls after that day with Yoon's aides, Kim Yong-hyun, head of the presidential security service and Lee Sang-min, the minister of public administration and safety who supervises the police.

Former Defense Minister Lee also received phone calls from then-national security adviser Cho Tae-yong and principal deputy national security adviser Kim Tae-hyo in the week following Aug. 2.

Lee's attorney, Kim Jae-hoon, told reporters Wednesday, "It is questionable whether providing these call records to the media was appropriate. Lee will not comment on the specifics because Lee doesn't think it's appropriate to go into the details. However, all of the allegations that have been raised in this regard are groundless."

The Corruption Investigation Office for High-Ranking Officials has been looking into allegations that the former defense minister exerted his influence to hold off the Marine Corps' internal probe into Chae's death and its transfer of the case to the police. The young conscript's death sparked suspicions that he was forced by his superiors to push ahead with the risky rescue operation without proper safety measures in place.

The CIO, therefore, plans to find out if they committed any possible illegalities during the conversations. Earlier, Oh Dong-woon, the new chief of the CIO, pledged a thorough probe into the alleged interference case related to the death of Chae, saying Yoon could, in principle, be subject to a summons. Oh made the remarks at a parliamentary confirmation hearing on May 17, saying that for a president, there are regulations for exceptions from criminal prosecution, unlike for the general public, but Yoon can "indeed be a subject of investigation."

Chae, 20, died after being swept away by an overflowing stream during a search-and-rescue operation for victims of heavy rainfall and flooding in Yecheon, North Gyeongsang Province, on July 19, 2023.