South Korea's ousted president has apologised to the people before being questioned over a corruption scandal that led to her removal from office.
The questioning of Park Geun-hye came 11 days after the country's constitutional court ruled unanimously to dismiss her as president over claims that she colluded with a confidante to extort money from businesses and committed other wrongdoings.
Her power had been suspended since she was impeached by parliament in December.
It was a dramatic fall for Ms Park, a daughter of murdered dictator Park Chung-hee, who was elected as the country's first female president in late 2012 amid a wave of support from conservatives who remembered her father as a hero who pulled the country up from poverty despite his suppression of civil rights.
"I am sorry to the people. I will sincerely undergo an investigation," Ms Park said when she arrived at a Seoul prosecutors' office.
She did not elaborate and went inside the building amid a barrage of camera flashes. Prosecutors later said they began questioning her with her lawyer present.
It was not clear if Ms Park's brief statement meant she acknowledged the corruption allegations, as she has repeatedly denied any legal wrongdoing.
South Korean politicians embroiled in scandals often offer public apologies for causing trouble though they deny their involvement.
South Korean media said prosecutors would probably not summon her again after Tuesday's questioning.
Dozens of high-profile figures including some top Park government officials and Samsung heir Lee Jae-yong have already been arrested or indicted in connection with the scandal.
Ms Park could face extortion, bribery and other criminal charges, but it is not known if prosecutors will seek to arrest her any time soon, especially ahead of an election in May to choose her successor.
Some experts say there would be a strong backlash from conservatives if she were to appear on TV dressed in prison garb and handcuffed.
Currently, Moon Jae-in, a liberal opposition leader who lost the 2012 election to Ms Park, now has a commanding lead in opinion surveys.
The scandal has divided South Korea for months, with millions of people taking to the streets and calling for Ms Park's removal in the largest public demonstrations in decades.
In recent weeks, pro-Park supporters, mostly elderly conservatives, have staged their own rallies.
Three people died in clashes between Ms Park's supporters and the police after the court ruled against her.
Earlier on Tuesday, hundreds of Park supporters waited for hours near her Seoul home, holding national flags and chanting her name as lines of police officers separated them from a group of reporters.
Stepping out of her home's black metal gate, Ms Park did not address to her supporters before getting into a black car, which followed a motorcade of police motorcycles to the prosecution office.
Ms Park had immunity while in office and had refused to meet prosecutors or allow officials to search her presidential compound.
She has since expressed defiance towards the allegations, saying: "I believe the truth will certainly come out."
The March 10 ruling has made Ms Park South Korea's first democratically elected leader to be forced out of office since democracy replaced dictatorship in the late 1980s.