The arrest of South Korea's president, explained

South Korean impeached President Yoon Suk Yeol arrives at the complex building housing the Corruption Investigation Office for High-ranking Officials (CIO) in Gwacheon on 15 January 2025. Photo: Yonhap / AFP

Explainer - South Korean investigators arrested impeached President Yoon Suk Yeol today for alleged insurrection over his bid to impose martial law, ending weeks of defiance and claims by Yoon and his lawyers that the arrest warrant was invalid.

Yoon and the Corruption Investigation Office for High-Ranking Officials (CIO), which is probing his short-lived martial law decree on 3 December, are at odds over whether the CIO has the authority to arrest and pursue criminal charges against a president.

Authorities now have 48 hours to question Yoon, before seeking a warrant to detain him for up to 20 days or releasing him.

Here is what we know about his arrest so far:

Who are the investigators?

The CIO is leading a joint investigation team involving police and the defence ministry seeking charges of insurrection and abuse of power against Yoon among others, while prosecutors carry out their own probe.

Police officers remove barbed wire fences around the presidential residence as they attempt to enter after a motorcade believed to be carrying South Korean impeached president Yoon Suk Yeol left earlier in Seoul on 15 January 2025. Photo: Yonhap / AFP

The CIO was launched in January 2021 as an independent anti-graft agency to investigate high-ranking officials, including the president, and their family members as part of efforts to keep prosecutors in check.

But its investigating and prosecuting rights are limited.

It does not have the authority to prosecute the president and is required to refer the case to the prosecutors' office to take any action, including indictment, once the questioning is over.

What is Yoon's argument?

Yoon said on Wednesday that he submitted himself for questioning to avoid any bloodshed despite what he called the illegality of the investigation and arrest.

South Korea's impeached president Yoon Suk Yeol. Photo: AFP / Ahn Young-joon

Yoon's lawyers have said that the CIO does not have the authority to handle his case as the law stipulates a wide-ranging list of high-ranking officials and violations it can investigate, but has no mention of insurrection.

Prosecutors capable of investigating insurrection charges have been carrying out a separate investigation on Yoon.

The lawyers also said that an arrest warrant granted by a Seoul district court was unconstitutional because it specified that the warrant was exempt from two clauses of the Criminal Procedure Act that limit the seizure and search of a place subject to confidential military information, or a public official possessing official secrets, without providing legal grounds.

They said any criminal investigation should be conducted after the Constitutional Court holds a trial on Yoon's impeachment and decides whether to remove him from office permanently.

Yoon's team has filed a complaint and an injunction with the Constitutional Court to review the warrant's legitimacy, though the Seoul Western District Court which issued the warrant has rejected a similar complaint.

On 3 January, the presidential security service and military guards blocked CIO investigators from arresting Yoon in a six-hour standoff.

Police and anti-corruption investigators arrive at the residence of South Korea's impeached President Yoon Suk Yeol in Seoul on 3 January 2025. Photo: Jung Yeon-Je / AFP

Its then chief, Park Chong-jun, had said that the security service could not cooperate on the warrant, citing the legal debate over the CIO's investigative rights and the warrant's validity.

What is the position of the CIO, police?

The CIO has said it has secured the right to take on Yoon's case by obtaining the arrest warrant, and the two clauses of the Criminal Procedure Act do not apply because the warrant was limited to arresting him, not seising his possessions.

Barbed wire and vehicles block the entrance to the compound of the presidential residence of impeached South Korean President Yoon Suk Yeol in Seoul on 15 January 2025. Photo: ANTHONY WALLACE/AFP

But the agency has [apologised for initially failing to arrest Yoon and requested police to take over the execution of the warrant, based on its consideration that "such a serious case as this one should not leave even the slightest possibility of controversy."

Police acknowledged there was a legal dispute over such a transfer but said they would consult the CIO.

The CIO and the police held multiple meetings to discuss how to execute the warrant after securing a re-issued warrant on 7 January.

Seok Dong-hyeon, Yoon's legal advisor, said the bid to transfer the execution of the warrant is effectively an admission by the CIO that its probe and the warrant were "illegal".

What do the courts say?

The Constitutional Court said on Monday it is reviewing the complaint and injunction filed by Yoon's lawyers.

A supporter of impeached South Korean president Yoon Suk Yeol holds a placard of Yoon and incoming US president Donald Trump during a rally near his residence in Seoul on 6 January 2025. Photo: AFP / Anthony Wallace

The Seoul Western District Court, dismissing a similar complaint previously, said that it was not illegal for the CIO to handle Yoon's case as allegations of insurrection are included in abuse of power charges covered by the agency.

It also said the warrant's exemption from the two Criminal Procedure Act clauses appears to confirm that any search that might entail was aimed at arresting the defendant, not seising his belongings, and it was not unconstitutional for a judge to specify that when approving a warrant.

Yoon's lawyers criticised the court's statement as "sophistry" and said they would consider appealing the decision to a higher court.

- Reuters