Former ruling People Power Party(PPP) Rep. Kwak Sang-do appeared for questioning by the prosecution over alleged high-profile bribery surrounding the Daejang-dong development scandal.

The Seoul Central District Prosecutors' Office on Wednesday began questioning Kwak as a suspect over an alleged violation of the Act on Regulation and Punishment of Criminal Proceeds Concealment.

Prosecutors are reportedly grilling Kwak about two-point-five billion won, or around one-point-nine million U.S. dollars, his son received from a firm at the center of the scandal in the form of severance pay and incentives.

The father and son are suspected of having an economic partnership, with the son paid the hefty sum by Hwacheon Daeyu Asset Management, where he worked until April 2021, in return for favors the former PPP lawmaker provided in 2015 during the bidding stage of the project.

Prior to Wednesday's questioning, Kwak denied all the allegations.

In February, the Seoul Central District Court acquitted the senior Kwak of bribery, saying it has not been proven beyond a reasonable doubt that the money paid to his son was part of a quid pro quo.

Appealing the ruling, the prosecution booked the son as an accomplice and applied the proceeds concealment charge against the father and son.