South Korea's impeached President Yoon Suk Yeol has spent his first night incarcerated as a pre-trial inmate at the Seoul Detention Centre after a court issued a formal detention warrant on Sunday to hold him for up to 20 days.

South Korea's impeached President Yoon Suk Yeol had his mug shot taken and underwent a physical check before spending his first night in jail as a criminal suspect, a prison officer said Monday.

SEOUL (Reuters) - A South Korean court granted on Sunday an extension of President Yoon Suk Yeol's detention, saying there was "concern" that Yoon could "destroy evidence" in a criminal probe related to his short-lived declaration of martial law in early December.