The chief of South Korea's top steelmaker Posco was grilled overnight by prosecutors until Saturday morning over an allegation that the sale of its former unit was related to an influence-peddling scandal involving President Park Geun-hye's close friend, prosecutors said.

Kwon Oh-joon, 66, returned home at about 7:10 a.m. after about 12 hours of intensive questioning at the Seoul Central District Prosecutors' Office, they said.

He is the first head of a major South Korean business group to be grilled by prosecutors looking into the snowballing political scandal.


He was grilled over allegations that an associate of Choi Soon-sil, Park's longtime friend, attempted to forcibly take over shares of the steelmaker's former advertisement subsidiary last year.

Choi's close associate Cha Eun-taek is suspected to have used his ties with Choi and other senior government officials to put pressure on a small ad agency, which acquired Poreka from Posco, to hand over 80 percent of its shares. The attempt, however, ended in failure, as the ad agency declined to cooperate.

Prosecutors tried to determine whether Kwon's decision to sell its money-making advertisement company was intended to help line Cha's own pockets from the beginning.

Whether Cha, Choi or any presidential officials intervened in the selloff process was the focus of the questioning, according to prosecutors.

A number of officials, including former senior presidential secretary An Chong-bum, have been put under custody for their alleged involvement in the process.

Prosecutors put Cha under detention late Friday on a charge of embezzling funds and attempting to extort shares from Posco's former affiliate. (Yonhap)