The state anti-corruption agency summoned for questioning a key suspect in its investigation into the military's controversial handling of the death of a Marine during a search and rescue operation last year.

The Corruption Investigation Office for High-ranking Officials(CIO) on Saturday began interrogating Marine Corps Commandant Lt.-Gen. Kim Gye-hwan on charges of power abuse and obstruction of exercise of a right.

Prior to questioning, Kim did not respond when asked whether he had said that President Yoon Suk Yeol was enraged about an initial Marine probe report to then-probe chief, Col. Park Jung-hun, or that he had heard that an order to hold off on transferring the report to the police had reflect the president's wishes.

Kim is suspected of playing a role in exercise of undue influence over the Marine investigation led by Park, who has claimed that he was told by Kim that the defense ministry is ordering deletion of names of suspects and applied charges in the probe report set to be sent to the police.

Kim allegedly said Yoon was outraged by the initial report, which included Lim Seong-geun, former commander of the Marine's First Division, as a suspect, adding that a press conference about the report was called off after the president's phone conversation with then-defense chief Lee Jong-sup.