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.

Hours after South Korea’s impeached President Yoon Suk Yeol was formally arrested, triggering rioting by his supporters, his lawyers said Sunday that he remains defiant in his refusal to answer questions over the probe into his declaration of martial law last month.