South Korean investigators on Wednesday detained the country's former health minister as they expand their inquiry into a corruption scandal involving impeached President Park Geun-hye.
The special prosecution team now has 48 hours to decide whether to request a formal arrest warrant for Moon Hyung-pyo.
Moon faces allegations that he pressured the National Pension Service to support a controversial merger deal between two Samsung affiliates last year, even though the fund's stake in one of the companies lost an estimated hundreds of millions of dollars in value.
Investigators also summoned Kim Sang-ryul, Park's former senior secretary for education and culture, to look into allegations that the presidential office kept a "blacklist" of cultural figures deemed as unfriendly to Park's administration and denied them state support.
South Korea's opposition-controlled parliament on Dec. 9 voted to impeach Park over allegations that she colluded with a longtime friend to extort money and favors from the country's largest companies and allow the friend to manipulate government affairs from the shadows.
Investigators have asked the Financial Supervisory Service to provide personal wealth statements of about 40 people who are suspected of helping Park's jailed friend, Choi Soon-sil, amass an illicit fortune through her connections with the president, Reuters reported.
Lee Kyu Chul, an official from the investigation team, led by special prosecutor Park Young-soo, didn't confirm who the 40 were or whether investigators were tracking the wealth Choi inherited from her late father, Choi Tae-min, a shadowy religious figure who emerged as Park Geun-hye's mentor in the 1970s.
At the time, Park was serving as acting first lady after her mother was killed in 1974 by a man trying to assassinate her father, military dictator Park Chung-hee, who was shot dead by his spy chief five years later. The Choi clan had long been suspected of using their ties with Park to filch from government officials and businessmen.
Samsung, the country's largest business group, is under suspicion that it sponsored Choi to win government backing for the merger that helped Samsung scion Lee Jae-yong promote a father-to-son transfer of leadership and boost corporate wealth at the group.
Samsung is one of the country's major business conglomerates that gave a combined 77.4 billion won ($64 million) to two nonprofit foundations Choi allegedly controlled and abused to expand her personal wealth.