The National Police Agency on Thursday released new guidelines for undercover investigators who use fake identification cards to apply for yami baito, or shady part-time jobs, in an effort to deter such crimes.

The NPA concluded that although such investigations involve the forgery of IDs, the practice is justifiable under the Penal Code and that they can be carried out under the current law.

The agency aims to introduce investigations in which undercover personnel use fake IDs as soon as implementation plans are formulated by prefectural police departments across the country.