In a tearful apology broadcast on Friday, Park said her "heart was breaking" over the political scandal in which a confidante is alleged of embezzlement and manipulating power from the shadows.

"It is hard to forgive myself and sleep at night with feelings of sorrow," Park, 64, said, her voice trembling.

The scandal centers on Park's old friend, Choi Soon-sil, who is alleged to have used her closeness to the president to meddle in state affairs.

The 60-year-old is also accused of coercing local firms - while using Park's name - into donating large sums to dubious non-profit foundations that she then used for personal gain.

Park faces closer scrutiny

Park, who was elected in 2013, agreed on Friday to be questioned about the scandal, adding that investigators should clarify what happened and that everyone involved should be held accountable, including herself, and take responsibility if found guilty.

On Thursday, a Seoul court formally approved an arrest warrant for Choi, on charges of fraud and abuse of power.

The President's lawyer has said he expects prosecutors to look into whether Choi inappropriately received classified documents.

Wild speculation

A media frenzy has followed the initial revelations, with some reports suggesting that Choi was still involved in a marginal religious group and that Park had fallen under its influence.

In Friday's address, Park denied being involved with a religious cult or that she had conducted shamanist rituals in the presidential Blue House.

Her popularity has plummeted to an all-time low of just five percent because of the scandal, according to a Gallup poll on Friday.

The leader of South Korea's main opposition party was quick to criticize Park's apology as lacking sincerity.

"The president should remove her hands from state affairs," said Choo Mi-ae, leader of Democratic Party of Korea.

mm/kl (AFP, AP, Reuters)