Park has been engulfed by a scandal that centers on Choi Soon-Sil, who is accused of using her personal ties with the president to coerce local firms to donate millions of dollars to non-profit foundations Choi then used for personal gain.
Choi, 60, is also accused of interfering in state affairs to the extent of nominating officials and editing Park's speeches even though she has no official title or security clearance.
Ahn Bong-Geun and Lee Jae-Man, who served as Park's key advisers until last month, are accused of helping Choi to visit the presidential office.
They also allegedly reported state affairs or leaked confidential documents to her, according to AFP.
Two other presidential aides have been arrested in the influence-peddling scandal which has sparked nationwide fury with hundreds of thousands of people taking to the streets to call for Park's resignation and mocking the president as Choi's "puppet".
