What you need to know about the attempt to arrest South Korea's Yoon

Here is what we know 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.

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 questioning is over.

WHAT IS YOON'S ARGUMENT?

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.

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 limits seizure and search of a place subject to confidential military information, or a public official possessing official secrets, without providing legal grounds.

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 rejected a similar complaint on Sunday.

On Friday, the presidential security service and military guards blocked CIO investigators from arresting Yoon in a six-hour standoff. The security service's chief, Park Chong-jun, said on Sunday 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 rights 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 seizing his possessions.

But the agency said on Monday it has requested police to take over 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."

A police official acknowledged that there was a legal dispute over such a transfer and that police officials would discuss it with the CIO.

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

WHAT DO COURTS SAY?

The Constitutional Court said on Thursday that it will begin reviewing the complaint and injunction filed by Yoon's lawyers as soon as a justice is assigned.

The Seoul Western District Court, dismissing a similar complaint on Sunday, 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 appear to confirm that any search that might entail was aimed at arresting the defendant, not seizing 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 will consider appealing the decision to a higher court.