A special counsel will investigate an online comment-rigging scandal in which Kim Kyoung-soo, a former Democratic Party of Korea lawmaker close to President Moon Jae-in, is suspected of being involved.

The National Assembly approved the special counsel bill for the scandal investigation Monday. It is the first case to be investigated by special counsel after the Moon administration was launched in May last year.

Investigation by special counsel will last for a maximum of 90 days. For now, its focus is suspected connection between Kim Dong-won, the jailed main culprit better known as his pen name Druking, and Kim Kyoung-soo.

Druking reportedly wrote a letter from prison and sent it to a local newspaper last week. In the letter, he alleged that in October 2016, Kim, then a ruling party lawmaker, visited his office, where he demonstrated a comment rigging program to Kim. It was a revelation that he and his accomplices obtained approval from Kim to manipulate online comments. The program enables a user to input multiple comments or likes on comments automatically.

Druking also wrote in the letter that he had forwarded daily lists of manipulated comments to Kim, who sometimes asked him why some comments ranked low on the list of most searched words.

His allegations run counter to Kim’s argument that he became aware of the existence of the program after news on the scandal broke out. At least one of them must be lying.

Druking may have trumped up the allegations in the letter to turn the case to his advantage. But some descriptions of circumstances in the letter seem to be very well founded. A possibility of his argument fitting the facts cannot be excluded.

Summoning Kim again or confronting him with Druking seems unavoidable if investigators are to verify what happened. Police have summoned Kim once to hear his testimony. Even after new suspicions arose afterwards, there has been no additional questioning of him.

Now the ball is practically in the special counsel’s court.

It is not time for Kim to prevaricate on Druking’s allegations against him with responses like “they are absurd, ridiculous and like a fiction,” and instead present evidence or refute them at the police voluntarily.

In the letter, Druking raised suspicions that the prosecution attempted to cover up the investigation. Such suspicions must not be ignored. Druking reportedly wrote, “On May 14, a prosecutor came in a room where another suspect was being interrogated, then instructed investigators there to leave out the suspect’s statements related to Kim.”

The prosecution rebutted the allegation immediately, calling it groundless, and added that Druking attempted a plea bargain, which was rejected because it is illegal in Korea, and that then he cooked up this claim. As the prosecution said it recorded the interrogations, it needs to open the recordings to the public.

If the police and the prosecution had done their jobs properly from the start, there would have been no reason for the special counsel investigation. They have dawdled since the scandal came to light in mid-April. Even after they found suspicious circumstances where Druking and his accomplices rigged online comments even before the presidential election last year, the investigation into them progressed too slowly. The prosecution turned back most police requests that it ask the court to issue arrest warrants for major suspects. Special counsel must get to the bottom of their possibly intentional foot-dragging.

So far, suspicions that Kim was involved in the scandal have come to surface, but many questions are still unanswered, such as whether that is all or whether other influential figures were involved. Special prosecutors must get to the root of the scandal.

Much evidence has probably been destroyed while the investigation has dawdled. Until the special counsel completes the preparations for its investigation, the prosecution and police will have to secure as much of the evidence that remains as possible, or face much tougher investigation.