South Korea's comprehensive special prosecutor has launched a second round of investigations into former President Yoon Suk-yeol and his inner circle.

The probe targets high-level officials to determine if the executive branch illegally used public funds to relocate the presidential residence. The investigation also explores potential links to an alleged insurrection, marking a significant escalation in legal scrutiny of the former administration.

Following an initial 90-day investigation phase [1], the special prosecutor has extended the probe by 30 days [2]. This extension allows investigators to focus on the "heavy tail" of the case, the senior-most officials involved in the decision-making process.

Authorities have already arrested two individuals, Kim Dae-gi and Yoon Jae-soon [3]. The prosecutor's office is now moving to summon other high-ranking figures to testify about the relocation budget and the suspected insurrection.

Former Minister Lee Sang-min is scheduled for a summons on the 4th of next month [4]. Former President Yoon Suk-yeol is scheduled to appear for questioning on the 6th and 13th of next month [5].

Investigators are also focusing on Kim Keon-hee, the wife of the former president, as part of the comprehensive review of the residence relocation funds. The probe seeks to establish whether the budget was diverted for personal or unauthorized purposes through the influence of the presidential couple.

Park Kwang-ryul of YTN News said the investigation into the emergency martial law and insurrection is now becoming fully operational.

“The probe targets high-level officials to determine if the executive branch illegally used public funds.”

The extension of the special prosecutor's mandate suggests that investigators have found sufficient preliminary evidence to justify a deeper dive into the former presidency. By targeting the 'heavy tail'—the top leadership—the probe shifts from examining administrative errors to potentially prosecuting criminal conspiracy and insurrection, which could lead to historic legal precedents for former heads of state in South Korea.