South Korean law enforcement officials requested a court warrant on Monday to detain impeached President Yoon Suk Yeol as they investigate whether his short-lived martial law decree on Dec. 3 amounted to rebellion.

The Corruption Investigation Office for High-Ranking Officials, which leads a joint investigation with police and military authorities into the power grab that lasted only a few hours, confirmed it requested the warrant from the Seoul Western District Court. They plan to question Yoon on charges of abuse of authority and orchestrating a rebellion.

Yoon Kap-keun, the president’s lawyer, denounced the detention attempt and filed a challenge with the same court, arguing that the warrant request was invalid. He also claimed the anti-corruption agency lacked the legal authority to investigate rebellion charges. Still, he evaded answering how the legal team would respond if the court approved the warrant for the president’s detainment.

“An incumbent president cannot be prosecuted for abuse of power,” the lawyer said. “Of course, there are differing academic opinions on whether a president can be investigated for abuse of power and some assert that investigations are possible. But even when investigations are allowed, the prevailing opinion is that they should be exercised with the utmost restraint.”

The anti-corruption agency didn’t immediately respond to the lawyer’s comments.

Han Min-soo, spokesperson of the liberal opposition Democratic Party, called for the court to issue the warrant, saying Yoon Suk Yeol’s detainment would be the first step toward “ending the rebellion and restoring normalcy.”

The warrant request came after Yoon dodged several requests by the joint investigation team and public prosecutors to appear for questioning and also blocked searches of his offices.

While Yoon has the presidential privilege of immunity from criminal prosecution, such protections don’t extend to allegations of rebellion or treason.

It’s not clear whether the court will grant the warrant or whether Yoon can be compelled to appear for questioning.

Under the country’s laws, locations potentially linked to military secrets cannot be seized or searched without the consent of the person in charge, and it’s unlikely that Yoon will voluntarily leave his residence if he faces detention. There are also concerns about possible clashes with Yoon’s presidential security service if authorities attempt to forcibly detain him.

Yoon’s presidential powers were suspended after the National Assembly voted to impeach him on Dec. 14 over his imposition of martial law, which lasted only hours but has triggered weeks of political turmoil, halted high-level diplomacy and rattled financial markets.

Yoon’s fate now lies with the Constitutional Court, which has begun deliberations on whether to uphold the impeachment and formally remove Yoon from office or reinstate him.

The National Assembly voted last week to also impeach Prime Minister Han Duck-soo, who had assumed the role of acting president after Yoon’s powers were suspended, over his reluctance to fill three Constitutional Court vacancies ahead of the court’s review of Yoon’s case.