It was a dramatic setback to Park, South Korea's first female President who rose to power four years ago amid conservatives' nostalgia for her late dictator father who is credited by supporters for pulling a war-torn country out of poverty in the 1960-70s. Liberal critics revile her father as a ruthless leader who tortured and imprisoned his opponents.
Earlier yesterday, hundreds of her supporters, mostly elderly conservative citizens, gathered near her Seoul home, waving national flags and chanting slogans when she left for the court.
Prosecutors say they want to arrest Park because her alleged crimes are "grave" and other suspects involved in the scandal, including her confidante Choi Soo Sil, have already been arrested.
In the coming weeks, prosecutors are expected to formally charge Park with extortion, bribery and abuse of power. A bribery conviction alone is punishable by up to life in prison in South Korea.
Park and Choi deny most of the allegations. Park has said she only let Choi edit some of her presidential speeches and got her help on "public relations" issues. Choi made similar statements.
The women, both in their 60s, have been friends for 40 years. Park once described Choi as someone who helped her when she had "difficulties", an apparent reference to her parents' assassinations in the 1970s. Park's father Chung Hee was gunned down by his own intelligence chief in 1979, five years after his wife was killed in an assassination attempt that targeted him. Park Geun Hye served as first lady after her mother's death.
South Korea will vote to choose Park's successor in May.
