The chairman of South Korea’s pension fund, Moon Hyung-pyo, has been arrested for alleged corruption acts involving Samsung and President Park Geun-hye.

State prosecutors said they raided the National Pension Service (NPS) chairman’s home on December 26, before arresting him on December 28.

The NPS is the world’s third-largest pension scheme.

Moon Hyung-pyo’s arrest comes amid President Park Geun-hye’s impeachment over the scandal involving her close friend Choi Soon-sil.

Image source Korea Herald

In the latest arrest, investigators are looking into NPS’s support of an $8 billion merger between two Samsung Group affiliates and whether Moon Hyung-puo used his influence as health minister at the time, to pressure it to back the deal.

The Ministry of Health and Welfare runs the pension service, which manages 545 trillion won ($451 billion) and was a major shareholder in Cheil Industries Inc and Samsung C&T Corp when they merged.

The NPS has denied previous reports that Moon Hyung-pyo pressured the organization to back the deal, and he told reporters on December 27 that he would cooperate with the investigation.

The scandal has also caught Samsung up in allegations that it backed foundations controlled by Choi Soon-sil in the hope of receiving political favors, which investigators are also examining.

Politicians voted this month to impeach President Park Geun-hye – a decision South Korea’s constitutional court has six months to uphold or overturn. Until then Park Geun-hye remains formally president but stripped of her powers, which are handed to the prime minister, a presidential appointee.

Park Geun-hye denies wrongdoing but has apologized for the way she managed her relationship with Choi Soon-sil, who also denies committing criminal offences.