South Korean police are formally building a case against impeached President Yoon Suk Yeol over accusations he obstructed the execution of an arrest warrant, a police spokesperson said on Friday.

South Korean President Yoon Suk Yeol contested his arrest on rebellion charges in one court and pleaded to preserve his presidency in the other, both cases related to his brief imposition of martial law.

South Korean President Yoon Suk Yeol is in court for a hearing where his lawyers are contesting his arrest on a criminal charge alleging he was orchestrating a rebellion when he imposed martial law.

South Korea's impeached President Yoon Suk Yeol appeared in a Seoul court on Thursday for his first trial hearing on charges of insurrection in the country's first criminal prosecution of an incumbent leader.

South Korea's ousted premier said on Thursday that he had opposed suspended President Yoon Suk Yeol's declaration of martial law, testifying for the first time at his former boss's impeachment trial about the events of a night that threw the country into turmoil.

South Korea's ousted President Yoon Suk Yeol on Wednesday became the country's first sitting head of state on trial on criminal charges.