Police have summoned former National Intelligence Service (NIS) chief Kim Kyu-hyun for questioning over suspicions that he sought to influence the Gangseo District mayoral by-election held on October 11, 2023. The allegations stem from the NIS's announcement that the Central Election Management Committee's networks were vulnerable to hacking just ahead of the election, raising concerns about the integrity of the voting process. The police are investigating whether this announcement was an attempt to interfere with the election, violating the Public Official Election Act and abusing authority.

The case was initiated following a complaint from Park Seon-won, a member of the Democratic Party and a former NIS official, who alleged that the NIS’s claims about hacking vulnerabilities were politically motivated. Park contended that the presidential office rejected a thorough security check prior to the by-election and that the questionable announcement was orchestrated by Kim Kyu-hyun to sway public perception about the election’s security. This points to serious implications regarding political interference in the electoral process.

As part of the ongoing investigation, police executed a search warrant at the NIS in January and have placed a travel ban on Kim Kyu-hyun. They are examining whether senior officials at the NIS manipulated security inspection results to create doubts about the election’s integrity, which may have led to the public's belief in election fraud narratives pushed by far-right groups. This incident raises significant questions about the role of intelligence agencies in domestic politics and the protection of democratic processes in South Korea.