Prosecutors in South Korea have charged ousted president Park Geun-hye and Lotte Group chairman Shin Dong-bin with bribery.
It is the latest twist to a corruption scandal that rocked the country for months.
Prosecutors claim Park colluded with Choi to receive seven billion won () from Lotte in return for favours.
Park is also charged with abuse of power and coercion by pressuring big businesses to contribute funds to non-profit organisations, it is claimed.
Lotte has denied allegations that it made improper deals with Park, or those linked to her, for favours.
South Korea’s biggest conglomerate has already been drawn into the inquiry.
Jay Y. Lee, the chief executive of the Samsung Group, is under arrest facing allegations of bribing Park and her friend, Choi Soon-sil.
All three are being held at detention centres.
Park, Lee, Choi and Samsung Group have also denied any wrongdoing.