She is known to have denied all charges during the questioning, though prosecutors did not confirm her stance.

Park's supporters were waiting for her from early in the morning, some stayed through the entire night, near the prosecution compound. Waiving national flags, they chanted, "Nullify the Impeachment!" as the car carrying her passed by.

A group of other supporters also gathered near Park's private home. Park smiled and waved to them as she arrived home.

Park was grilled over multiple allegations, including that local business groups donated huge sums of money to two foundations allegedly controlled by Park's friend Choi Soon-sil in return for business favors.

Prosecutors summoned Choi and two of Park's jailed former aides -- An Chong-bum and Jeong Ho-seong -- on Tuesday, but all three declined the call, citing personal reasons. Prosecutors refused to comment on whether the summons was for a cross-examination with the former president.

Prosecutors will now mull over whether to seek an arrest of the ex-leader. They have so far avoided directly mentioning the possibility of seeking Park's detention.

Park is the country's fourth former president to undergo questioning over criminal allegations, following Roh Tae-woo, Chun Doo-hwan and the late Roh Moo-hyun.

"I feel sorry to the public," Park said as she arrived at the prosecution. "I will faithfully go through the interrogation." (Yonhap)