SEOUL, South Korea >> South Korean President Park Geun-hye has ordered 10 of her senior secretaries to resign amid an investigation that she let an old friend, the daughter of a religious cult leader, interfere in important state affairs.

The announcement by Park’s office came before thousands were expected to turn out in anti-government protests planned in Seoul on Saturday over the scandal that is likely to deepen the president’s lame duck status ahead of next year’s elections.

Park has been facing calls to reshuffle her office after she admitted on Tuesday that she provided longtime friend Choi Soon-sil drafts of her speeches for editing. Her televised apology sparked huge criticism about her mismanagement of national information and heavy-handed leadership style many see as lacking in transparency.

There’s also media speculation that Choi, who holds no government job, meddled in government decisions on personnel and policy and exploited her ties with the president to misappropriate funds from nonprofit organizations.

Prosecutors on Saturday widened their investigation by searching the homes and offices of presidential officials suspected of interacting with Choi, South Korea’s Yonhap news agency said. Park’s office, however, denied that prosecutors searched the Blue House — the presidential office and residence. Prosecutors had previously summoned some of Choi’s key associates and raided their homes and workplaces and also the offices of two nonprofit foundations Choi supposedly controlled.

The saga, triggered by weeks of media reports, has sent Park’s approval ratings to record lows and the minority opposition Justice Party has called for her to resign. The Minjoo Party, a larger opposition party which has refrained from calling for Park’s resignation over fears of negatively affecting next year’s presidential vote, said Park’s decision to shake up her secretariat was too little and too late and called for stronger changes, including the reshuffling of her Cabinet.

Park’s aides on the way out include Woo Byung-woo, senior presidential secretary for civil affairs, and Ahn Jong-beom, senior secretary for policy coordination. Lee Won-jong, Park’s chief of staff, tendered his resignation on Wednesday.

Woo has been blamed for failing to prevent Choi from influencing state affairs and has also been embroiled in separate corruption allegations surrounding his family.

Ahn, whose home and office were reportedly searched by prosecutors on Saturday, is under suspicion that he helped Choi pressure South Korean companies into making large donations to the Mir and K-Sports foundations, launched in October last year and January this year, respectively. Choi reportedly masterminded the creation of the two nonprofits, which managed to gather around $70 million in corporate donations over a short period of time, and is suspected of misappropriating some of these funds for personal use.

Park’s office said she plans to announce a new lineup of senior secretaries soon.

Choi’s lawyer Lee Gyeong-jae said that she was currently in Germany and is willing to return to South Korea if prosecutors summon her. In an interview with a South Korean newspaper earlier this week, Choi admitted receiving presidential documents in advance, but denied intervening in state affairs or pressuring companies into donating to the foundations.

Choi and Park reportedly became friends in the 1970s when Choi’s late father, Choi Tae-min, a shadowy religious figure who was a Buddhist monk, cult leader and Christian pastor at different points of his life, emerged as Park’s mentor.

At the time, Park was serving as acting first lady after her mother was killed in 1974 by a man trying to assassinate her father, military strongman Park Chung-hee, who would be murdered by his own spy chief five years later.