South Korean President Yoon Suk Yeol, 64, became the first sitting president to be arrested after investigators breached his residence’s security on Wednesday.
Yoon faces charges of insurrection related to a failed martial law order in December, which led to nationwide turmoil.
His impeachment by parliament is suspended pending a ruling by the Constitutional Court.
Yoon’s arrest ended a weeks-long standoff after investigators, who had previously failed to apprehend him in January, arrived at his residence with a large team and tools to scale barricades and cut through barbed wire.
Before his arrest, Yoon claimed in a video that the investigation was illegal but stated he would cooperate to prevent violence. During questioning, he remained silent.
His lawyers argue that the arrest was unlawful, as the anti-corruption agency, the CIO, lacks jurisdiction over insurrection charges.
Opposition leaders hailed the arrest as a step toward restoring justice and democracy.
Currently, Finance Minister Choi Sang-mok serves as acting president.
Yoon can be held for up to 48 hours without a new warrant, after which authorities may detain him for up to 20 days.
Pro-Yoon supporters have protested outside the investigation office.