The prosecution and the National Police Agency are in conflict over criminal investigations again, this time over the prosecution’s rejection of a police request to ban a former vice justice minister from going on an overseas trip. The prosecution says the former vice minister, Kim Hak-ui, is a witness, not a criminal suspect yet.

The police agency, which is investigating a sex-for-favors case, recently asked the prosecution to ban more than 10 people involved in the case from going out of the country. But the prosecution turned down half the requests. Among those spared an overseas travel ban was Kim, who denied being involved in the case. He resigned from the post of vice minister on March 21, saying that the mere mention of his name in connection with the case made it impossible to continue his work.

The police agency suspects that Kim was given an undue favor just because he was a senior prosecutor before he was appointed to be vice justice minister. As the police agency is preparing to submit the request for a ban on his overseas trip again, the prosecution accuses the agency of attempting to take advantage of the news media’s coverage of the event at a time when little progress is being made in its investigation.

Indeed, the police agency’s investigation hit an impasse when the National Forensic Service failed to identify a person in video footage that was taken as evidence against Kim. The video footage was obtained when a businesswoman pressed charges of rape and extortion against a construction company executive, who was suspected of arranging sexual services for Kim and other high-ranking government officials in return for business favors.

The construction company executive had previously been taken to the prosecution to be questioned about three criminal cases in which he had allegedly been involved, only to be acquitted each time. The police agency does not rule out the possibility of an invisible hand having worked behind his acquittals, given that he would not have arranged banquets and sex services for nothing.

But what the police agency needs to do is speed up its investigation. Of course, the prosecution will have to assist the police agency in conducting the investigation. It will have to guard against engaging in a squabble, as they have often done in the past over the police agency’s demand for greater autonomy in investigations it launches on its own.