Unlicensed Chinese moving company arrested by police officer fluent in Chinese = South Korea

A Korean police officer, using his experience studying in China during his university days, detected the conversation between the Chinese men and arrested them at the scene of the crime. On the 9th, the Seoul Gangbuk Police Station arrested two Chinese men, Mr. A (24 years old) and Mr. B.
The police announced that they have filed charges against Lee Gi-taek (25 years old), a police inspector at the Suyu 3 Police Station of the Gangbuk Police Station, on suspicion of violating the Transportation Business Act and the Immigration Control Act, and are currently investigating the matter.
At around 11:13 a.m. on the 24th, police were dispatched to an officetel in Suyu-dong, Gangbuk-gu after receiving a report that "similar cargo was being transported without permission."
Upon arriving at the scene, they found Mr. A's Starex vehicle with the trunk open. The driver and passenger were
The space except for the seats had been modified to carry cargo, but there was nothing inside when police arrived. A said in Korean, "I came to visit my friend's house and just brought a chair."
However, as Inspector Lee continued to pursue him, Mr. A called his business partner Mr. B and told him in Chinese, "Say you did it without compensation." Mr. A said that the Korean police officers had been involved in their affairs.
He said he thought he couldn't understand what was being said. Inspector Lee is fluent in Chinese, having studied in China for about four years while in college and worked in the foreign affairs division for four years and six months after joining the police force.
Using Mr. A’s conversation as a clue, Inspector Lee identified the location where Mr. B was moving his belongings, and after checking their remittance history, he voluntarily accompanied them to the police station.
During the investigation, the Gangbuk Police Station found that they had entered Korea on a student visa (D-2) and engaged in cargo transportation without permission, resulting in them being charged with "activities outside the scope of their stay permit."
It was revealed that Lee had been working in the Foreign Affairs Division to support multicultural families. During the COVID-19 pandemic, he worked with civilian interpreters.
They have also created and distributed a translated version of the "Coronavirus Checklist."