Special prosecutors said Saturday they will summon the de facto leader of Samsung Group for additional questioning over his alleged involvement in the high-profile corruption scandal that has rocked the country for the past several months.

Lee Jae-yong, who has already been arrested formally, will be brought to the special prosecutor‘s office Sunday to face questioning over allegations he offered 43 billion won ($36.3 million) in bribes to Park’s friend Choi Soon-sil in exchange for business favors.

It would mark his fifth appearance before the special prosecutor since he was arrested on bribery charges on Feb. 17. He has since been behind bars.

Prosecutors believe Lee gave or promised some 43 billion won ($36.3 million) worth of bribes to President Park Geun-hye‘s jailed friend Choi Soon-sil in return for the government’s backing of a merger of two Samsung affiliates in 2015.

The merger was seen as critical for the smooth management succession of the group from ailing Samsung Electronics Chairman Lee Kun-hee to his only son, Jae-yong.

The younger Lee is known to be denying all charges leveled against him.

Choi, the central figure in the scandal, is accused of using her close ties with Park to strong-arm Samsung and other local conglomerates to offer large “donations” to nonprofit foundations, which she allegedly used for personal gain.

The investigation team has been accelerating the probe as its deadline is slated for Tuesday.

The special counsel has asked Acting President and Prime Minister Hwang Kyo-ahn to extend the period by a month, but it is unclear whether he will approve the request.

Prosecutors plan to indict Lee on bribery charges within this month if the request is not accepted.

Also on Saturday, prosecutors called in Choi to question her over allegations that she amassed illicit wealth and was illegally involved in personal affairs of a private bank in return for favors.

(Yonhap)