The election commissions of Korea and their employees have the authority to investigate any violation of the Public Official Election Act or Political Funds Act, to collect evidence of violations, and to ask the person in question to present him/herself at the EC office. When they suspect a violation, election officials may request relevant institutions to submit financial transaction and communication records. Administrative fines may be imposed as a result of election law violations, and a halt or correction order or warning may be issued. When a halt or correction order or warning is not carried out, or when there are election law violations that are deemed to greatly harm the integrity of an election, the case will be brought to the prosecutor’s office.
The 1987 Constitution of South Korea introduced an independent specialized court for constitutional disputes in addition to the Supreme Court. Based on the Constitution, the functions of the Constitutional Court include deciding on the constitutionality of laws, ruling on competence disputes between governmental entities, adjudicating constitutional complaints filed by individuals, giving final decisions on impeachments, and making judgments on dissolution of political parties.
Election dispute resolution is divided into two types according to who reviews and rules on the case. Election petitions are dealt with by the relevant election commission, and election lawsuits are dealt with by the relevant court. Both types of litigation cover the validity of the election itself and the election result.
Election petitions are a prerequisite procedure before an election lawsuit only used in local elections, where there are many objections raised due to a large number of constituencies and candidates. They were introduced to ease the burden on the courts when there is an objection against the validity of an election or an election result in local elections. The National Election Commission rules on elections for Si/Do mayors or governors and proportional representation members of Si/Do councils, while the relevant Si/Do election commission rules on all other local elections. Decisions are issued within 60 days of a petition being submitted.
Election lawsuits happen when an objection is raised against the validity of an election or an election result (for presidential and legislative elections), or when a petitioner appeals against a ruling on an election petition (for local elections). The Supreme Court is competent for presidential and National Assembly elections, elections for proportional representation members of Si/Do councils, elections for mayors and governors of Si/Do. Relevant High Courts are competent for elections for constituency members of Si/Do councils, Gu/Si/Gun council members and the heads of Gu/Si/Gun governments. Rulings are issued within 180 days of a lawsuit being filed.
Sources:
https://www.nec.go.kr/engvote_2013/01_aboutnec/01_summary.jsp
https://www.constituteproject.org/constitution/Republic_of_Korea_1987.pdf