The gravest are bribery charges. Park is suspected of colluding with her longtime friend Choi Soon-sil in forcing dozens of local conglomerates to "donate" a total of 77.4 billion won ($70 million) to two dubious foundations -- Mir and K-Sports -- allegedly controlled by Choi.

Samsung, among others, is accused of giving or promising some 43.4 billion won to Choi, and in effect to Park, as kickbacks in return for business favors. Of the total, 20.4 billion won went to the two foundations.

If convicted, Park can be sentenced to 10 years or more in prison.

Park is also accused of being involved in blacklisting cultural figures deemed critical of her policies and prohibiting government agencies from providing financial support to them. Her former close aides were arrested for their roles in creating and managing a list of more than 9,000 artists, writers, filmmakers and entertainment figures.

Prosecutors allege that the former president abused her power by pressuring her aides to sack culture ministry officials who resisted discriminatory measures against those on the blacklist.

She is also suspected of exerting undue influence on private companies' personnel management and hectoring them to sign contracts with Choi's firms, according to prosecutors.

The country's food and entertainment conglomerate, CJ, for one, was told to dismiss its vice chief executive for movies and TV content apparently supportive of liberal politicians, they said.

South Korea's top carmaker, Hyundai Motor Co., was also pressured to sign a 1.1 billion won supply contract with a mid-sized company belonging to one of Choi's associates and another 7.1 billion won advertising deal with an agency owned by Choi, prosecutors said.

Telecoms firm KT Corp. was allegedly bullied to hire executives close to Choi and to award a 6.8 billion won advertising deal to her agency.

Steelmaker POSCO was compelled to create a fencing team and to sign yet another contract with one of Choi's companies, though that contract was not realized in the end.

Prosecutors are looking into whether the business groups were seeking favors in return. The conglomerates, however, have been claiming that the president and her aides twisted their arms to make such decisions favorable to Choi.

Prosecutors also said Park allegedly violated the law on managing government secrets by leaking them to Choi.

There have been suspicions that Choi was involved in making key state decisions, despite having no policy experience. Park's longtime aide Jeong Ho-seong is currently standing trial and in custody for his alleged role in the process.

Park moved out from the presidential office, Cheong Wa Dae, earlier this month after the Constitutional Court removed her from office in a historic ruling on March 10. (Yonhap)