A woman who is accused of acting as South Korea's "shadow president" was jailed on Tuesday under the country's emergency detention laws. Choi Soon-sil – accused of fraud and interfering in state affairs – was detained and questioned for hours on Monday night.

Prosecutors said she was "unstable" after questioning her, reported Al Jazeera. "There is a possibility of Choi trying to destroy evidence as she is denying all the allegations. She is also in an extremely unstable psychological state, and it's possible an unexpected event could occur if she is released," said a prosecution official.

Choi has been friends with President Park Geun-hye for more than 40 years. Apart from being involved in state affairs without holding a government post, she is also accused of using her influence to extort $69 million (Rs 460 crore approximately) from top corporate houses as donations for her two foundations, reported The New York Times. Prosecutors also conducted raids at eight banks to collect information on the financial transactions with which Choi was involved.

After scores of people protested against the scandal and demanded Park's resignation, the president on Sunday issued a public apology and carried out a partial rejig of the key aides who are accused of being linked to Choi. According to reports, she may form a neutral multi-party Cabinet to restore public trust.