Former South Korean President Yoon Suk Yeol is back in custody over an independent investigation into his declaration of martial law last year.

According to the independent counsel leading the probe, the Seoul Central District Court approved a warrant for Yoon’s re-arrest early Thursday morning, because of concerns over the destruction of evidence.

Yoon’s shocking December declaration plunged South Korea into a constitutional crisis and was widely condemned as striking at the heart of the nation’s democracy. He reversed course within six hours, after lawmakers forced their way into parliament and voted unanimously to block it.

Yoon was detained in January on charges of leading an insurrection, becoming the first president in South Korean history to be arrested while in office. He was released in March after the Seoul court canceled his arrest warrant for technical reasons.

In April, the Constitutional Court unanimously ruled to remove Yoon from office, calling his actions a “grave betrayal of the people’s trust.”

He has since faced multiple criminal investigations. According to the independent counsel, Yoon is now facing charges including abuse of power and obstruction of official duties.

In a leaked warrant request, the counsel alleged that Yoon declared martial law in an attempt to overcome political gridlock caused by the opposition party’s majority in the National Assembly and its impeachment of several senior officials.

He is accused of deploying troops to block lawmakers from entering the national assembly building to overturn the decree and of giving orders to “break down the doors” of parliament and “drag people out, even if it takes firing guns.” Yoon’s lawyers deny he ordered the use of firearms.

The counsel also alleges that Yoon instructed his commander to prioritize the arrest of key political figures, including the then opposition leader Lee Jae-myung, who is now the country’s president. He is further accused of ordering the presidential security service to obscure communication records from secure phones used afte the martial law was lifted.

In addition, Yoon is accused of obstructing warrant executions by the Corruption Investigation Office (CIO) in December and January by mobilizing the presidential security detail and authorizing the use of force.

Yoon’s lawyers said the warrant request was “rushed and unjustified” and called the investigation “flawed and politically motivated.” They said the independent counsel’s questions during Yoon’s investigation were only at a basic level regarding the allegations, and that the warrant request did not include any treason charges.

They added that most individuals involved have already been detained and are standing trial, so all relevant evidence has been secured and there is no risk of evidence being destroyed.

Independent counsel teams were established to investigate Yoon following his removal from office, and the election of Lee in a snap presidential election in June.