Prosecutors probing the Sung Woan-jong bribery scandal summoned and questioned Rep. Hong Moon-jong over allegations that he received illegal political funds from the late construction tycoon.

Hong flatly denied the allegations before and after he underwent questioning for 16 hours until early Tuesday morning. He told reporters that Sung ― the former CEO of Keangnam Enterprises ― who once was a fellow parliamentarian, had asked for help regarding his convictions for election law violations and in the party nominations for the general election. “But I never accepted any money from him,” Hong said.

Never in our memory have politicians who were subpoenaed for suspicions of receiving illegal money admitted the allegation, yet many of them have ended up in jail.

Even without the numerous past cases, there is enough grounds to suspect that Hong received illicit money from Sung, who pinpointed the ruling party lawmaker and seven other politicians as recipients of his money shortly before committing suicide in April.

Sung specifically said that he gave 200 million won ($180,000) to Hong ― then Saenuri secretary-general and a key manager of President Park Geun-hye’s campaign ― before the 2012 presidential election. He made it clear that he gave the money to help with the Park campaign.

Later, a key financial aide to Sung told prosecutors that, following orders, he gave 200 million won to a senior Saenuri official in the same year. This once led to speculation that the money was identical to the amount mentioned by Sung.

But as it turned out, the aide handed over the money to the Saenuri official in March 2012, one month before the parliamentary elections. This made it clear that the money was different from the 200 million won Sung claimed he gave to Hong.

This means that Sung’s claims that he gave Hong and two other campaign managers ― Incheon Mayor Yoo Jeong-bok and Busan Mayor Suh Byung-soo ― a total of 700 million won before the last presidential election still stand firm.

Hong’s questioning by the prosecutors must be a step toward getting to the bottom of the allegations, not a means to exonerate the three from the accusations. Both Yoo and Suh also must be summoned for questioning in this regard.