SEOUL (AFP) - South Korean President Park Geun Hye is facing calls to resign over allegations she allowed a close personal friend to meddle in state affairs.
The woman at the heart of the scandal, Ms Choi Soon Sil, is an elusive figure with no government post or security clearance but a reportedly Rasputin-like grip on the president's trust and affections.
Here are five key questions about an ongoing and sometimes bizarre scandal that has gripped the country and severely undermined Ms Park's public stature and ability to govern.
1. Who is Choi Soon Sil?
Ms Choi, 60, is daughter of the late Choi Tae Min, a shadowy religious figure who married six times, had multiple pseudonyms and set up a cult-like group known as the Church of Eternal Life.
Mr Choi befriended a traumatised Ms Park after the 1974 assassination of her mother, who he said had appeared in his dreams asking for his help.
Mr Choi became a key mentor for the young Ms Park, a role that angered a number of key aides to her father, the country's then military ruler Park Chung Hee.
Mr Park was assassinated in 1979 by his intelligence chief who cited Mr Park's failure to step between Mr Choi and his daughter as one reason for his actions.
Ms Park also formed a close bond with Mr Choi's daughter Soon Sil that endured after Mr Choi's death in 1994.
Ms Choi's former husband served as a top aide for Ms Park until her presidential victory in 2012.
Ms Choi is officially being investigated for using her ties with Ms Park to coerce companies like Samsung to make large donations to two non-profit foundations she set up - allegedly for her personal benefit.
There was also widespread anger over accusations that Ms Choi's daughter had received preferential treatment as a student at one of the country's top universities.
3. The power behind the president?
But the more damaging side to the scandal is that Ms Choi, who has never held any official position, seemingly exerted enormous influence over the President's political policy-making.
Files obtained from Ms Choi's personal computer by broadcaster JTBC TV suggest Ms Choi edited some of Ms Park's key speeches and received confidential documents, including files related to ties with Japan and North Korea.
Some reports have suggested Ms Choi had her own coterie of aides who advised the President on appointments, policy issues and even on her wardrobe.
The scandal has seen Ms Park's approval ratings plummet to record lows, even after she made a public apology for "causing concern to the people".
It has played into long-standing criticism of Ms Park's aloof decision-making process and her perceived tendency to ignore expert advice and surround herself with loyalists.
4. Religious cult?
And the quasi-religious mystique surrounding Ms Choi has been especially troubling.
Lawmakers, including some in Ms Park's own party, have voiced concern that the president is under the spell of a "religious cult," with Ms Choi acting as some sort of shaman after taking on her father's mantle as a Rasputin-like adviser.
The head of the main opposition Minjoo Party said it was like discovering you were being ruled by a "terrifying theocracy".
5. Can Park still govern?
Ms Park, who has just over a year left in office, has apologised but vowed to stay put.
For the moment, the main opposition party has pushed for a special probe but stopped short of calling for Ms Park's impeachment, perhaps, analysts suggest, for fear of triggering a backlash.
But the scandal has severely undermined Ms Park's ability to govern effectively at a time of slowing economic growth, rising unemployment and tensions with North Korea.
A recent poll showed 70 per cent of voters wanted the president to resign or be impeached.
Ms Choi is currently holed up in Germany, having left South Korea in early September as the first reports of her influence-peddling emerged.
In a newspaper interview, Ms Choi denied any wrongdoing, saying she had only helped Ms Park "out of good faith".
Ms Choi's lawyer says she is well aware of the "gravity" of the situation and is willing to return home to be questioned and punished "if she did anything wrong".