Seoul, South Korea—— Lawyers representing South Korea's impeached president, who was detained by anti-corruption officials over last month's ill-fated declaration of martial law, will refuse further questioning, insisting the investigation is illegal, his lawyer said Thursday.

South Korean President Yoon Seok-yeol was questioned for more than 10 hours on Wednesday at the headquarters of the Senior Officials Corruption Investigation Office and exercised his right to remain silent after being detained at his official residence in Seoul during a massive law enforcement operation.

Investigators are expected to arrest him in the coming days.

The anti-corruption agency, which is conducting a joint investigation with the police and military into whether Mr Yin's declaration of martial law constitutes rebellion, has 48 hours to ask the court to formally arrest him or release him.

Yoon's lawyers argued that the detention order issued by the Seoul West District Court was invalid and asked the Seoul Central District Court to consider releasing him.

The clock on the arrest warrant has been suspended while the court reviews his petition, which could take up to 48 hours. As part of the review, Yoon is likely to attend a hearing at Central District Court. Court records show a hearing is scheduled for Thursday at 5 p.m., indicating a ruling could come sometime in the evening.

On December 3, Mr Yoon attempted to break the legislative deadlock by declaring martial law and deploying troops around the National Assembly, triggering the country's worst political crisis since democratization in the late 1980s. The standoff lasted only a few hours before lawmakers managed to resolve the issue. Break the lockdown and vote to remove the measure.

His presidential powers were suspended when the opposition-dominated parliament voted on December 14 to impeach him and charge him with rebellion. His fate now depends on the Constitutional Court, which has begun deliberations on whether to formally remove Yoon Eun-hye or dismiss the charges and reinstate him.

Yin and his allies have ignored efforts to investigate his role in the Dec. 3 chaos. He ignored requests to appear for trial for weeks and remained at his official residence to avoid detention as his lawyers resisted police, citing laws protecting the location. The search without the consent of the person in charge, Yin, may be related to military secrets. They also said the anti-corruption agency had no legal authority to investigate allegations of insurrection.

Yoon also resisted an attempt to detain him when the presidential security services sealed off the residence. He was eventually detained about five hours after hundreds of anti-corruption investigators and police raided the presidential palace for the second time.

In a video recorded shortly before being escorted to the anti-corruption agency's headquarters, Yin lamented that "the rule of law in this country has completely collapsed." He agreed with his lawyers that the anti-corruption agency had no jurisdiction to investigate his conduct but said he was being detained to prevent violence.

The Constitutional Court rejected a request by Yoon's lawyers to postpone a hearing in the case scheduled for Thursday. Even while in custody, Yin may still exercise his right to attend.

If the court approves Yin's formal arrest, anti-corruption investigators can extend his detention to 20 days, during which time the case will be handed over to prosecutors for prosecution.

Park Sung-bae, a lawyer specializing in criminal law, said if prosecutors indict Yoon on charges including rebellion and abuse of power, he may remain under arrest until the court makes its first ruling, which usually takes six months Made within. Under South Korean law, rebel leaders could face the death penalty or life imprisonment if convicted.