Prosecutors raided the offices of Samsung Electronics for allegations that the company had illicitly provided finance assistance to Choi's daughter who was a former member of the national equestrian team.

Samsung is suspected of having provided 2.8 million euros (about $3 million) to a company in Germany co-owned by Choi and her daughter. The 20-year-old is also alleged to have received improper favors in entering a prestigious university.

Prosecutors will bring to court the case of Choi on Nov. 19, who is suspected of peddling undue influence for personal gains and intervening in government decisions behind the scenes. The 60-year-old Choi is a private citizen without any security clearance and public position.

In addition to charges of abuse of power and fraud filed against Choi, the prosecution was quoted by local media as saying that it will investigate further wrongdoings, including bribery and influence peddling, for possible indictments later on.

All of 53 conglomerates, which made donations to the Mir and K-Sports foundations, will also be investigated by prosecutors. Chairmen of the conglomerates could be summoned for questioning if necessary.

The prosecution's special investigative unit in charge of probe into the Choi Soon-sil case launched an investigation on Monday into President Park's closed-door meetings with seven of the conglomerate chiefs held in the presidential office in July last year.

Public attention is centered on whether the embattled president would be investigated over the political scandal. Park said in her address to the nation last Friday that she would accept a direct probe into herself "if necessary."