Prosecutors investigating political favor allegations surrounding a lucrative development project in Seongnam are grilling four key figures in the scandal for a second day on Thursday. 

Authorities are speaking with Kim Man-bae, Nam Wook and Jeong Young-hak - private partners in the project - as well as Yoo Dong-gyu, the former acting president of Seongnam Development Corporation.

Prosecutors are interrogating the figures to shed light on allegations that the city-run developer gave preferential treatment to private investors in exchange for bribes. 

Earlier on Wednesday, prosecutors questioned the four, focusing on how permits were issued for the development project. 

Based on Thursday’s results, prosecutors will decide whether to request an arrest warrant for Kim and Nam. They’ll also assess whether to indict Yoo on charges of bribery, embezzlement and misappropriation before his detainment period is up on Friday.