1.

Criminal Justice Reform: Separating Investigative Authority from Prosecutorial Authority

On October 2, 2026, the Prosecutors’ Office will be abolished and replaced by two new bodies: the Public Prosecution Office (the “PPO”), responsible solely for prosecution, and the Serious Crimes Investigation Agency (the “SCIA”), which will be exclusively responsible for investigating serious crimes. The National Assembly passed the Public Prosecution Office Act (the “PPO Act”) and the Serious Crimes Investigation Agency Act embodying these sweeping changes in prosecutorial powers on March 20, 2026 and March 21, 2026, respectively, and both were promulgated following deliberation by the State Council on March 24, 2026.

At the core of the reform is the organizational separation of the investigative and prosecutorial authority that the prosecution has until now exercised together. Under the PPO Act, the principal powers and duties of a PPO prosecutor will be limited to filing and maintaining indictments, reviewing warrant requests, and consulting with and supporting the judicial police in criminal investigations. Prosecutors will also lose their authority to direct investigations conducted by special judicial police officers within administrative agencies such as the Korea Customs Service (the “KCS”).
 

2.

Abolition of Prosecutors’ Authority to Direct Special Judicial Police Investigations

Customs officials who investigate customs offenses under the Customs Act are designated as special judicial police officers under the Act on the Persons Performing the Duties of Judicial Police Officers and the Scope of Their Duties (the “Judicial Police Duties Act”). In that capacity, they investigate violations of the Customs Act, the Act on Special Cases Concerning the Implementation of Free Trade Agreements, the Foreign Trade Act, the Foreign Exchange Transactions Act, the Act on the Aggravated Punishment of Specific Economic Crimes, the Act on Regulation and Punishment of Criminal Proceeds Concealment, the Food Sanitation Act, the Cosmetics Act, and the Medical Devices Act — and, to date, they have done so under the direction of a prosecutor (see Articles 5(17) and 6(14) of the Judicial Police Duties Act).

The PPO Act changes this. Article 4, which sets out the duties and powers of a PPO prosecutor, provides in subparagraph 3 only for consultation with and support for judicial police officers in criminal investigations; it does not extend to directing or supervising special judicial police officers. Consistent with this, Article 56(1) and (2) characterize the relationship between a PPO prosecutor and the judicial police as cooperative rather than directive. The Criminal Procedure Act has since been amended along the same lines: the prosecutor’s authority to “direct” special judicial police investigations under current Article 245-10(2) is replaced by a “duty of cooperation” between the prosecutor and the special judicial police officer with respect to investigations and the filing and maintenance of indictments.

Customs officials acting as special judicial police officers will therefore investigate customs offenses independently, free from prosecutorial direction. All cases will nonetheless be referred to the PPO, which retains the final authority over indictment.
 

3.

Changes to Investigation System of KCS

These reforms make changes to the investigation system of the KCS’s special judicial police unavoidable. 

The KCS will move from a relationship in which it was subject to the direction of a prosecutor—from the initial investigation stage through the stage of the KCS’s referral to the prosecution—to a horizontal, cooperative one. Its special judicial police will be able to decide whether suspicion exists, whether the evidence is insufficient, and whether to refer a case with a recommendation to prosecute. As the KCS’s special judicial police’s authority and role will expand, including investigating smuggling (import/export), customs duty evasion, illicit reduction/refund, violations of the Foreign Exchange Transactions Act, narcotics, and trade security, the KCS is likely to strengthen its investigative capacity to guard against the weakened enforcement — and resulting public harm — that could otherwise follow the abolition of prosecutorial direction.

The KCS has already moved quickly. In February of this year, it established a Trade Security Investigation Team at headquarters and Trade Security Investigation Divisions at the Busan and Incheon Customs Offices, and it continues to expand its investigative departments and personnel.

As part of such efforts, the KCS is undergoing various internal reorganizations, including the following:
 

(1)

Have legal experts at the principal main customs offices such as Seoul, Busan, Incheon Airport, and Incheon legally review and inspect procedural legality at the stage prior to the referral to the PPO of cases investigated by the KCS’s special judicial police;

(2)

Establish a standing and specialized advisory system, composed of experts in the fields of academia, the legal profession, criminal justice, and human rights, concerning the investigations of the KCS’s special judicial police; 

(3)

Establish within the KCS, a department that can strengthen the consistency and accountability of investigations; and

(4)

Expand the functions of the offense investigation deliberation committees of each main customs office and institutionalize, more transparently, the procedures for deliberating on objections raised by parties concerned in a case.
 

4.

Implications – Corporate Response Strategies Toward Investigations by KCS’s Special Judicial Police

For now, companies will need to follow closely how criminal procedure operates in practice once the PPO and the SCIA are launched and the amended Criminal Procedure Act takes effect.

At the same time, this reform will bring unprecedented change to the KCS’s investigation system, with its special judicial police functioning as an independent investigative agency no longer subject to prosecutorial direction. Companies exposed to KCS investigations will therefore need to respond on the basis of a sound understanding of the new system.

Several practical points follow. First, although prosecutorial direction has been abolished, the view of the PPO prosecutor at the stage of requesting search-and-seizure and detention warrants is still expected to be an important variable in the direction of a KCS investigation. Second, even where the customs authorities refer a case with a recommendation to prosecute, the indictment decision rests with the PPO prosecutor. Adherence in KCS investigations to core criminal justice principles — due process, the warrant requirement, a strict standard of proof, and the exclusion of illegally obtained evidence — will accordingly matter more than before. Third, because the amended Criminal Procedure Act no longer recognizes the PPO prosecutor’s authority to conduct supplementary investigations, the prosecutor will decide whether to indict on the basis of the KCS’s investigation file alone. Practice will shift as a result, and the strategy appropriate to the PPO may differ from the one companies previously adopted toward the Prosecutors’ Office.

During the transitional period, before practice under the new system settles, companies should also anticipate greater procedural uncertainty and significant delays.

Companies that become subject to customs investigations will therefore need a tailored and sophisticated response at every stage of the process, through to the conclusion of the case, so as to avoid unforeseen and unjust outcomes. Such a response depends on a high level of familiarity with the KCS’s new enforcement structure and practice, and with customs criminal practice from the KCS through the PPO to trial before the courts.