South Korean investigators raided the offices of Samsung Group on Wednesday as they widened the probe into the alleged influence-peddling by embalmed president Park Geun-hye.
The Yonhap news agency reported that the prosecutors suspect President Park and her scandal-ridden close confidante Choi Soon-sil had a role in the merger of two Samsung Group affiliates through the national pension fund.
The prosecutors also raided the offices of the National Pension Service (NPS), South Korea's largest pension fund. The fund has been under the scanner after it approved the $8 billion merger of Samsung C&T Corporation and Cheil Industries.
The Samsung Group and the NPS confirmed the raids took place but did not give further details, Reuters reported.
Park and Choi had faced allegations that they had put pressure on large South Korean conglomerates like Samsung to fund the sports and cultural organisations allegedly run by Choi and her family. After weeks-long protests, Choi and An Chong-bum, a former aide to Park, were indicted on Sunday and charged with abuse of power.
Wednesday's raid at Samsung Group and the NPS came after prosecutors questioned Korea Racing Authority (KRA) Chairman Hyun Myung-kwan over allegations that he facilitated the Samsung funding of Choi's equestrian daughter Chung Yoo-ra.
Hyun had earlier worked as the chief secretary for Samsung Electronics Chairman Lee Kun-hee and he is a personal friend of Choi. The Samsung funding was aimed at helping promising equestrians train in Germany in preparations for the 2020 Tokyo Olympics. Under the plan, the Samsung Group had promised a fund outlay of $15.8 million, South Korean news outlet KBS said.
Earlier the prosecutors had probed if Choi gained access to classified documents using her friendship with the president and made personal monetary gains through non-profit foundations. South Korean media says Choi collected as much as 80 billion won ($92 million) in purported donations from businesses for her non-profit organisations.
Park and Choi have been close friends for almost 40 years. The 60-year-old Choi is the daughter of a South Korean religious leader and one-time mentor of Park, Choi Tae-min.