Seoul. South Korea’s jailed ex-President Yoon Suk Yeol again refused to attend questioning by investigators Friday, using a new method to resist: He took off his prison uniform and lay down on the floor in his detention room.

Yoon, removed from office in April over his ill-fated imposition of martial law, was sent back to prison last month as he stands a high-stakes trial over rebellion and other charges. Yoon, a conservative, faces investigations into other criminal allegations that are not related to his Dec. 3 martial law decree but target him, his wife, and others.

On Friday, Min Joong-ki, a special counsel named by his liberal rival and new President Lee Jae Myung, sent investigators to retrieve Yoon from a detention center near Seoul after the former president twice defied requests to attend questioning. Min's team is tasked with delving into allegations surrounding Yoon's wife, Kim Keon Hee, including that she and her husband exerted inappropriate influence on the then-ruling party's election nomination process in 2022.

Min's team had a court-issued detention warrant that authorized them to bring Yoon out of his detention facility by force, but said they were hoping for his voluntary cooperation.

“Without wearing his prison uniform, the suspect lay down on the floor and strongly resisted his detention,” assistant special counsel Oh Jeong-hee told a televised briefing.

Oh said her team members refrained from using physical means out of safety concerns, but notified Yoon that they would execute the warrant next time. She urged Yoon to cooperate, as the Korean people are closely watching whether the enforcement of the law is applied to everyone equally.

Yoon's lawyers earlier said Yoon was unable to attend his trial and undergo questioning by investigators because of health problems. They said in a statement Thursday that Yoon has cardiovascular, autonomic nervous system, and eye issues. They cited an unidentified hospital as saying that Yoon faces the risk of blindness because he failed to receive medical treatment for the past three months.

Yoon's imposition of martial law, which brought armed troops into Seoul streets, lasted only a few hours before lawmakers voted down his decree unanimously.

Yoon has argued his decree was a desperate attempt to draw public support for his fight against the “wickedness” of Lee's Democratic Party, then the main opposition party, which had obstructed his agenda, impeached top officials, and slashed the government’s proposed budget.