This article was displayed on the ChosunBiz RM Report site at 2:40 p.m. on Sept. 8, 2026.
Prosecutors of the Corruption Investigation Office for High-ranking Officials (CIO) and prosecutors of the Public Prosecution Service are both "prosecutors" under the law. But can a prosecutor of the Public Prosecution Service tell a CIO prosecutor to "redo the investigation because it is insufficient"? With the revised Criminal Procedure Act set to take effect next month, the CIO and the Ministry of Justice are at odds over this issue.
According to legal sources on the 8th, the CIO recently expressed opposition during a subcommittee discussion of The National Assembly's Legislation and Judiciary Committee to a plan that would allow prosecutors of the Public Prosecution Service to demand supplemental investigations from CIO prosecutors. The gist is that because both Public Prosecution Service prosecutors and CIO prosecutors are prosecutors under the law, it is not appropriate for one side to demand supplemental investigations from the other.
Instead, the CIO is said to have requested a separate procedure so that, if the Public Prosecution Service determines additional investigation is needed, it can "commission" the CIO to do so. The Ministry of Justice, by contrast, says the Public Prosecution Service should be able to demand supplemental investigations in cases where the CIO cannot bring charges directly.
◇No basis to send it back even if the investigation is lacking
Under the current CIO Act, the CIO can directly indict only crimes by the chief justice, Supreme Court justices, the prosecutor general, judges and prosecutors, and police officials at the rank of senior superintendent general or higher. For other high-ranking official cases, after completing the investigation, it must transfer the case to the prosecution and request indictment.
The problem is that the current Criminal Procedure Act defines the target of a prosecutor's demand for supplemental investigation as a "judicial police officer." A CIO prosecutor is not a judicial police officer. Even if the prosecution, after receiving a case from the CIO, decides the investigation is insufficient, there is no clear legal basis to demand that the CIO investigate again.
A representative example is the 2023 bribery case worth about 1.5 billion won involving a Board of Audit and Inspection executive that the CIO handed over to the prosecution. The prosecution demanded a supplemental investigation from the CIO, saying additional investigation was needed, but the CIO refused, saying "there is no legal basis."
To conduct additional investigation directly, the prosecution sought search-and-seizure and communications warrants, but the court also rejected them, citing a lack of legal basis. In the end, no supplemental investigation was conducted, and the prosecution indicted only the 290 million won portion out of the alleged 1.58 billion won. The rest was not indicted.
◇Law was changed, but a "supplemental investigation gap" remains
The revised Criminal Procedure Act taking effect next month also failed to resolve this issue, because the target of supplemental investigation demands remains defined as a "judicial police officer."
A prosecutor of the Public Prosecution Service may hear from parties related to the case or receive materials to verify facts. But statements or materials obtained in this process cannot be used as evidence at trial. This is why there is criticism that there is no adequate means to substantively supplement a case when the CIO's investigation is insufficient.
In legal circles, some argue that a separate supplemental procedure is needed for cases the CIO cannot indict directly. Because the investigating body and the body that decides whether to indict are different, there should be a mechanism to supplement the case when the Public Prosecution Service finds the investigation lacking.
A prosecutor at a district prosecutors' office in the capital area said, "Since, for matters where the CIO has no right to indict, its legal status can be seen as that of a judicial police officer, it should be subject to judicial control." The Presidential Committee on Policy Planning is also said to have discussed measures last year such as allowing demands for supplemental investigation, requests for reinvestigation, or demands for corrective action in such cases.
In legal circles, there is also the view that even if the CIO's independence is guaranteed, for cases in which the CIO does not have the right to indict, an institutional mechanism is needed for the Public Prosecution Service, which decides whether to indict, to supplement insufficient investigations.
Lee Seong-il, a professor at Konkuk University Law School, said, "Without separate institutional supplementation, confusion could grow from October over how to handle cases coming from the CIO," adding, "Procedures should be clarified to supplement cases with insufficient investigations without undermining the CIO's independence."