President Yoon Suk Yeol is seen inside a vehicle being transferred to the Seoul Detention Center in Uiwang, Gyeonggi Province, Jan. 15, after completing his first day of questioning. Yonhap

As President Yoon Seok Yeol continues to refuse requests to appear for questioning, the Corruption Investigation Office for High-ranking Officials (CIO) attempted to carry out compulsory apprehension procedures in order to forcibly bring him in for interrogation.

After the Seoul Western District Court approved his arrest warrant early Sunday, Yoon did not respond to the CIO's request to appear for questioning, which was originally scheduled for 10 a.m. Monday. This marks the fourth time the president has refused to cooperate with the CIO's investigation since he was hauled off to a detention center last Wednesday.

"Given the current situation, the CIO is seriously considering bringing him in [for questioning] by force," a CIO official told reporters on Monday.

Although the current law lacks specific provisions allowing for the compulsory apprehension of an arrested suspect, the CIO believes it is possible, citing a 2013 Supreme Court precedent.

Later in the day, investigators from the CIO went to the detention center in an attempt to forcibly bring the president in for questioning, but they returned without him after trying until almost 10 p.m.

"This afternoon, several CIO officials entered the area of the detention center where the president is being held. They attempted to forcibly bring him to the CIO office for questioning," Seok Dong-hyeon, one of Yoon's legal counsels, said in a statement to reporters. The lawyer added that Yoon was busy at the time, consulting with his legal team for his impeachment trial.

Reporters gather outside the Corruption Investigation Office for High-ranking Officials at Government Complex Gwacheon in Gyeonggi Province, Monday. Yonhap

To obtain meaningful statements, the CIO maintains that in-person questioning with Yoon is essential.

The CIO also requested a ban on visitors for Yoon, citing concerns over evidence tampering. As a result, the president is permitted to meet only with his legal counsel and no one else.

While the CIO was initially expected to investigate Yoon until Friday, it now believes it can continue questioning him until Jan. 28. This extension accounts for the four days lost due to Yoon's petition for a detention review and the subsequent warrant review hearing.

The investigative body plans to transfer Yoon to a special prosecution team after approximately 10 days of investigation. Since prosecutors can extend the detention period of an arrested suspect by another 10 days, Feb. 7 is expected to be the expiration date for Yoon's arrest warrant.

As of Monday afternoon, no decision has been made regarding when the case will be sent to the prosecution, and discussions were still underway.

Police heighten security as they control public access to the Constitutional Court in central Seoul, Monday. Yonhap

Yoon's lawyers said the president will attend the third hearing of his impeachment trial at the Constitutional Court on Tuesday.

Mindful of protesters who stormed the Seoul Western District Court following the approval of the arrest warrant for the president, the Constitutional Court stated it would enhance security measures to protect the court justices.

"The protection of Constitutional Court judges is currently ensured, with police officers accompanying the judges. If necessary, we will strengthen the security measures further," an official from the court said.