Oh Dong-woon, the nominee for the chief of the Corruption Investigation Office for High-Ranking Officials, pledged on Sunday to strengthen the agency's role as an independent investigative body and ensure its effectiveness.

“I have a heavy heart because I have been nominated as the chief of the CIO during a difficult time,” Oh told media while en route to his office in Gwacheon, Gyeonggi Province, south of Seoul, on Sunday, to prepare for his confirmation hearing at the National Assembly.

“If I become the head of the CIO, I will work hard to establish the CIO as an independent investigative agency and become an effective organization," he said.

The CIO was launched in January 2021 to independently investigate corruption cases involving former and current high-ranking public officials, including the president, lawmakers and prosecutors, as the only investigative body aside from the prosecution endowed with the authority to indict.

President Yoon Suk Yeol on Friday nominated Oh, the former judge who transitioned to become an attorney, as the new head of the CIO. The nomination comes three months after the inaugural CIO chief, Kim Jin-wook, retired following a three-year term.

The appointment was also announced amid continued criticism of the CIO's sluggish performance, underscored by just one guilty sentence out of three indictment cases in the last three years.

When questioned by reporters about the issues facing the anti-corruption agency, Oh replied, "While I haven't received an official report yet ... from what I've gathered through media reports, it seems that the public feels a sense of fatigue and a lack of efficacy (in regard to the CIO)."

Oh went on to say, "If I become the chief, I will work hard to change the organization so that it can be revitalized and establish itself as an independent investigative agency."

Since its establishment in 2021, two of the CIO's cases ended up in acquittals while in the third case, Son Joon-sung, the deputy chief prosecutor of the Daegu High Prosecutors' Office, was sentenced to one year in prison in the first trial by the Seoul Central District Court.

Also, none of the CIO's five requests for arrest warrants have been granted by courts so far.

Nominee Oh, if successfully appointed, will face a backlog of cases that he needs to work on, including the high-profile investigation into the circumstances surrounding the death of Marine Cpl. Chae Su-geun last July.

Oh told reporters on Sunday "The CIO plans to faithfully investigate (cases) in accordance with laws and principles" when asked about how the CIO plans to cope with "politically sensitive cases," including Chae's death.

Chae, 20, died while 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.

The CIO has been looking into allegations that former Defense Minister Lee Jong-sup exerted influence to recall the sending of files collected during the Marines' internal probe into Chae's death to the police. Chae'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.

When asked about his ability to maintain impartiality as the CIO's head after being nominated by the ruling party, Oh replied that he was "recommended by the parliamentary recommendation committee and underwent a lengthy selection process."

Oh further stated, "Regardless of the recommendation's origin, I am dedicated to faithfully fulfilling my duties as the leader of the independent investigative body."

Presidential spokesperson Kim Soo-kyung said Yoon would promptly request the National Assembly to hold a confirmation hearing for Oh, during a press briefing on Friday. Although Assembly approval is not required for his appointment, the Assembly will still conduct a confirmation hearing for the nominee.