Kim had already resigned after the brief imposition of martial law late Tuesday by President Yoon Suk Yeol, which saw soldiers and helicopters sent to parliament.

Yoon was forced to rescind the order hours later and parliament voted down his decree.

Kim had already been slapped with a travel ban.

Police have launched an investigation into Yoon and others for alleged insurrection.

The prosecutors' office was not immediately available for comment on Kim's arrest, reported by the Yonhap news agency and other local media outlets Sunday morning.

Late Saturday Yoon survived an impeachment motion in parliament despite huge street protests outside.

Opposition parties proposed the impeachment motion, which needed 200 votes in the 300-member parliament to pass, but a near-total boycott by Yoon's People Power Party (PPP) doomed it to failure.

The PPP said after the vote that it had blocked the impeachment to avoid "severe division and chaos", adding that it would "resolve this crisis in a more orderly and responsible manner".

Party leader Han Dong-hoon said that the party had "effectively obtained" Yoon's promise to step down, and said until this happened he would "be effectively excluded from his duties", leaving the prime minister and party to manage state affairs.

The impeachment outcome disappointed the huge crowds -- numbering 150,000 according to police, one million according to organisers -- demonstrating outside parliament for Yoon's ouster.