Impeached South Korean President Yoon Suk Yeol on Thursday refused to attend a second day of questioning after being detained over his declaration of martial law, according to local media.

Yoon’s lawyers said he did not intend to comply with investigators’ orders to undergo additional questioning, citing concerns over his physical well-being. His team also said that he already explained his position during Wednesday’s questioning and had nothing else to say to investigators.

Yoon was taken into custody on Wednesday morning at his presidential palace after a standoff between investigators and the presidential security team. Yoon then sat through 10 hours of questioning with the Corruption Investigation Office for High-ranking Officials (CIO), who stated that he remained silent throughout the questioning.

The Seoul Western District Court issued an arrest warrant for the impeached president on December 31, which permits investigators to detain Yoon for up to 48 hours after being taken into custody. After those 48 hours are over, investigators must either request a warrant for his formal arrest, which will allow them to detain him for up to 20 days, or release him.

The Presidential Security Service (PSS) previously blocked an attempted execution of the arrest warrant, which led to the resignation of the PSS chief. The warrant was re-issued after investigators failed to detain the president before the initial warrant expired on January 6.

Yoon’s defense team claims that the warrant is invalid, arguing that the Seoul Western District Court did not have the proper jurisdiction to issue it. His team has asked the Seoul Central District Court to review the warrant’s legality, and the court is expected to issue its decision Thursday evening.

The CIO is investigating Yoon on charges of insurrection and abuse of power related to his declaration of martial law on December 3. Yoon claimed that the Democratic Party, the opposition party in control of the National Assembly, was aligned with North Korean communist forces. The National Assembly quickly lifted the martial law order and impeached the president, finding that he violated Article 77 of the South Korean Constitution. Article 77 limits martial law to situations of war, armed conflict, or similar national emergencies.

According to Article 65 of the nation’s constitution, the Constitutional Court has until June 2025 to determine whether to officially remove Yoon from office or reinstate him. The court’s impeachment proceedings began on Tuesday.