Former South Korean President Yoon Suk Yeol is back in a solitary cell after a court approved a new arrest warrant. He is facing an investigation over his declaration of martial law last year.

Yoon, who was the first sitting South Korean president to be arrested, faces trial on charges of leading an insurrection over his attempt to impose martial law. During Wednesday's seven-hour hearing, a special counsel team argued for the arrest warrant on five key charges, South Korean news agency Yonhap reported.

Former President Yoon Suk Yeol, already ​accused of insurrection, faced additional ​criminal charges after a special counsel expanded the investigation into his ill-fated declaration of martial law.