Arrested South Korean President Yoon Seok-yeol will not attend a new round of questioning by investigators on Friday, his lawyer said, as authorities faced a deadline to obtain a warrant to extend his detention or release the embattled leader.

To extend Yoon's detention, investigators are expected to ask the court on Friday for a detention order of up to 20 days, legal experts said.

On Wednesday, Yun became the first sitting South Korean president to be arrested on whether he was guilty of rebellion during the brief imposition of martial law in early December. He is being held at the Seoul Detention Center.

Although Yoon's lawyers challenged the legality of the arrest, the Seoul Central District Court late Thursday rejected the challenge and ruled that the arrest was legal.

The Corruption Investigation Office (CIO), the top official leading the criminal probe, recalled Yoon for questioning on Friday, but his lawyer said the suspended president would not attend.

"He fully stated his basic position on the first day (of the arrest), and we believe there is no reason or necessity to answer question-and-answer questions back and forth," Yoon's lawyer Seok Dong-hyeon said in a statement.

Mr Yin also refused to be questioned on Thursday and has been blocking his interrogation.

Authorities have 48 hours to question the impeached president before they must release him or seek a warrant to detain him for up to 20 days.

The 48-hour countdown is expected to end on Friday night after it was paused to allow a court to review challenges to his arrest, Yonhap news agency said, citing the chief information officer.

Shi said on Friday that investigators were expected to seek a detention order, adding, "We hope that the court will consider more carefully and comprehensively" the "illegality" of the arrest when reviewing the detention order.

South Korea is grappling with its worst political crisis in decades, triggered by Yoon Eun-hye's brief imposition of martial law on Dec. 3, which was rejected by parliament.

While the United States criticized Yoon for declaring martial law, national security adviser Jake Sullivan warned last week that nuclear-armed North Korea could try to take advantage of the political situation in Seoul.

North Korea has largely avoided public comment on the situation in Seoul, but state media reported Yin's arrest on Friday, two days after the incident.

"Rodong Sinmun" quoted foreign media reports as saying that this is the first time that South Korea has arrested a sitting president.

"Yin Seok-yeol did not sacrifice national order for his personal interests and followed legal procedures," the newspaper said.

In December, North Korea's state news agency KCNA called Yin's attempt to impose martial law a "crazy" act that triggered "dictatorship over the people."