Seoul, Nov 20 (IANS) The South Korean Prosecutor's Office on Sunday said President Park Geun-hye is involved in a serious case of corruption and influence-peddling at the centre of which is her friend and advisor.

The team of prosecutors investigating the case said they have pressed charges against Choi Soon-sil, a friend of the president who has been in prison since October for abuse of authority and for having pressurised companies to donate large sums of money to two nonprofits, Efe news reported.

The case, known as "Choi Soon-sil Gate", has sparked outrage among citizens who have been holding massive protests every week since the scandal broke out, demanding the president step down.

An Chong-bum, former senior secretary for policy coordination, was also indicted for allegedly collaborating with Choi in the process, Yonhap News Agency reported.

Jeong Ho-seong, who served as former senior secretary for private presidential affairs, will also stand trial on charges of handing over governmental and presidential documents to Choi.

The two are among Park's top aides who resigned late last month in the wake of the scandal.