• Yoon could be first president to be arrested while in office

• His martial law declaration triggered a constitutional crisis

A South Korean court on Tuesday issued an arrest warrant for embattled President Yoon Suk Yeol, who has been suspended from power over his short-lived martial law declaration, according to investigators.

If the warrant is executed, Yoon would be the first president in South Korea’s history to be arrested while still in office. A joint investigation team made the request on Monday after Yoon defied a third summons to appear for questioning.

Shortly after the warrant was approved, the presidential security service said security measures will take place in accordance with law, without elaborating. Yoon’s lawyer did not immediately respond to a request seeking comment.

Yoon’s martial law declaration has plunged South Korea into its worst constitutional crisis in decades, pressuring financial markets, disrupting diplomatic efforts and ultimately leading to his impeachment on Dec. 14. Political uncertainty has only intensified since then with the suspension of Prime Minister Han Duck-soo, who replaced Yoon as acting president.

It’s not immediately clear if the investigators would manage to take the president into custody. A previous attempt by the police to search the presidential office was blocked by Yoon’s office.

The investigation team said it hasn’t decided when to execute the warrant. While investigators typically have up to seven days to carry out an arrest warrant, according to an official, it is unclear how long the warrant for Yoon remains valid.

Yoon’s representatives previously said the investigation team doesn’t have legal grounds to seek a warrant for the president.

Kweon Seong-dong, floor leader of Yoon’s People Power Party, said trying to detain a sitting president through an emergency means of an arrest warrant is not an appropriate investigation method. The opposition party asked the ruling party to stop defending Yoon and instead cooperate to resolve the situation.

Yoon has signaled his intent to fight in court to stay in office, saying his martial law decree was within his constitutional powers. He’s facing a trial that will decide whether to reinstate or permanently remove him from office. The court has until June to make a ruling, with the next hearing scheduled for Jan. 3.

As the political turmoil deepens, the country is dealing with the aftermath of a Jeju Air flight crash on Sunday, which killed all but two of the 181 people onboard. Acting President Choi Sang-mok, who took on the role after Han’s impeachment, has declared a week-long mourning period until Jan. 4.