Former President Park Geun-hye was questioned by prosecutors Tuesday over a string of corruption allegations that removed her from office earlier this month.
Park appeared at the Seoul Central District Prosecutors' Office in southern Seoul at around 9:30 a.m. as a suspect of various charges including bribery, abuse of power, coercion and leak of government secrets.
"I feel sorry to the public. I will faithfully go through the interrogation," she said as she arrived at the prosecution.
Sources said Park denied all charges during the questioning, though prosecutors declined to confirm her stance.
She did not exercise her right to remain silent, according to a senior prosecution official.
Prosecutors are expected to grill Park 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.
Lee Jae-yong, the de facto leader of Samsung Group, was arrested and indicted over suspicions of giving bribes to Choi, and in effect to Park. He has been flatly denying the charges.
Prosecutors summoned Choi and two of Park's jailed former aides -- An Chong-bum and Jeong Ho-seong -- on the same day, but all three rejected, citing personal reasons.
The senior prosecutor, who asked not to be named, declined to comment on whether their summons were for a cross-examination with the former president.
When asked whether they are considering seeking to arrest Park, he said, "We are concentrating on the interrogation at the moment."
Her lawyer Son Bum-kyu said earlier in the day the questioning will not be recorded or videotaped as Park and her attorneys did not agree to the procedure.
Two of Park's lawyers were on standby to take turns in accompanying her during the inquiry, which watchers say could continue past midnight.
Police tightened security around the prosecution office, mobilizing some 2,000 officers nearby for contingencies. Access to the compound was restricted to officials and reporters who went through prior security checks.
Park's supporters gathered near the complex and her private home from early in the morning, chanting slogans, such as "Nullify the impeachment!"
Near another gate of the prosecution compound, those against Park gathered and chanted for her arrest.
Park has so far effectively rejected undergoing a direct investigation, but the Constitutional Court's decision to oust her earlier this month stripped her of the immunity that had protected her from criminal prosecution.
A number of former aides have been questioned and put on trial over their alleged involvement in the scandal, meanwhile.
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.
Roh Moo-hyun committed suicide in 2009 amid an investigation into allegations that his family members accepted illicit funds. (Yonhap)