Samsung Group leader Jay Y. Lee appeared at the South Korean special prosecutor's office for questioning on Monday as part of a wider investigation into an influence-peddling scandal that could topple President Park Geun-hye. The special prosecutor has focused on South Korea's biggest conglomerate, accusing Lee in his capacity as Samsung chief of pledging 43 billion won ($37.31 million) to a business and organizations backed by Park's friend, Choi Soon-sil, in exchange for support for a 2015 merger of two Samsung companies. The funding included sponsorship for the equestrian career of Choi's daughter, who is under arrest in Denmark after being sought by South Korean authorities. Park, Lee, Choi, and Samsung Group [SAGR.UL] have all denied bribery accusations. Proving illicit dealings between Park or her confidantes and Samsung Group is critical for the special prosecutor's case that ultimately targets Park, analysts have said. Park was impeached by parliament in December and South Korea's Constitutional Court will decide whether to uphold that decision. She has been stripped of her powers in the meantime. Lee arrived at the prosecution office in southern Seoul early on Monday in a black sedan, dressed in a dark blue suit and tie and flanked by Samsung Group officials and his lawyer. "I will once again tell the truth to the special prosecution," Samsung Group's third-generation leader told reporters before entering an elevator. He gave no details. Outside the prosecutor's office, protesters held up signs calling for his arrest.