South Korean police on Monday booked the current acting president Choi Sang-mok for charges relevant to insurrection, triggered by the impeached President Yoon Suk-yeol's martial law declaration, according to multiple media outlets.

A civic group, called Candlelight action, filed a complaint against Choi, who also serves as minister of economy and finance and became acting president following the impeachment of both Yoon and the prime minister, for his participation in a plot to commit the rebellion and his connivance at the insurrection.

The special investigative unit of the National Office of Investigation reportedly booked Choi and others earlier in the day for treason-relevant charges.

It was known that Choi participated in a cabinet meeting to endorse the emergency martial law, which was declared by Yoon on the night of December 3 but was revoked by the National Assembly hours later.

The police reportedly asked the impeached Prime Minister Han Duck-soo, who also took part in the cabinet meeting, to appear for questioning for the second time, becoming the first cabinet member to be interrogated by the police twice over the martial law imposition.

Han was impeached on Friday after refusing to appoint three constitutional court justices, who will fill vacancies on the nine-member bench for Yoon's impeachment trial.

The impeachment motion against Yoon was passed in the National Assembly on December 14 and was delivered to the constitutional court to deliberate it for up to 180 days, during which Yoon's presidential power is suspended.

To oust Yoon from office, at least six out of nine constitutional court justices are required to uphold the impeachment motion.