Korean police want me to take a drug test after my friend's arrest — I'm an E-2 teacher, do I have to?

A "voluntary" request means what it says: you are not legally required to attend, and you are not legally required to give a sample. That does not make ignoring it a good plan, because the police have a second route, and how you handle this week affects which route they take. On your other question — use of cannabis before you ever came to Korea, by a non-Korean, outside Korea, is not an offense under Korean law. That distinction is the center of your situation, and it needs to be handled carefully rather than assumed.

What this is under Korean law

Cannabis use and possession are offenses under the Narcotics Control Act (마약류관리법, mayangnyu gwalli-beop). Use of cannabis carries up to five years' imprisonment or a fine of up to KRW 50 million. Korea's rules are strict and there is no "personal use" tolerance.

Territorial scope matters for you. Under Article 2 of the Criminal Act, Korean law applies to offenses committed within Korea, by anyone. Under Article 3, it also applies to Korean nationals for acts committed abroad — which is why Korean citizens are prosecuted for cannabis use in countries where it is legal. A foreign national's conduct outside Korea, before arriving, is not covered. A hair test that shows use predating your arrival is therefore not, by itself, evidence of a Korean offense — but it is also not something an investigator will simply take your word on, and the timing argument has to be made properly.

How the process works in Korea

What you received is a request for a voluntary investigation (임의수사, imui susa). You may decline to attend, and you may decline a urine or hair test. The police cannot compel a sample without a warrant (압수수색영장, apsu susaek yeongjang) issued by a court. Whether they seek one depends on what they already have — typically, messages in your friend's phone and his statement about who was present.

If a sample is taken and positive, or if other evidence supports use in Korea, the police can send the case to the prosecutor (송치, songchi). If not, they close it with a non-referral (불송치, bulsongchi). First-time cannabis use cases in Korea, where the prosecutor does proceed, often end in a suspension of indictment (기소유예, giso yuye) conditioned on treatment education, or a suspended sentence; those are ranges, not promises.

Your situation as a foreign national

Two things a foreign resident should assume from the first contact. A departure suspension (출국정지, chulguk jeongji) under Article 4 of the Immigration Act can be requested during a drug investigation, and drug cases are where it is used most readily; your flight in six weeks is not protected by the fact that you booked it. And drug convictions are among the grounds listed for deportation review under the Immigration Act — a principle worth knowing, though the outcome in any individual case is decided by the Immigration Office, not the police or the court.

Your school: police do not routinely notify employers of a voluntary interview. They may contact the school to confirm your address or employment. A conviction or fine is a different matter; it can surface at renewal, and E-2 sponsors are sometimes informed. MEGA X handles the criminal side; where the case touches your status, we coordinate with an immigration specialist as part of your defense.

You have the right to an interpreter. Do not rely on the investigator's English.

What to do now, and what not to do

Do not go in this week, alone, and take a test "to clear things up." Do not reply to the KakaoTalk with explanations. Do not delete messages; deletion is visible and reads as concealment. Do not contact your arrested friend about what he said. Speak to a lawyer, who will contact the investigator, establish what the request is actually based on, and decide with you whether and how to attend — including whether a test, given your timeline, is in your interest or against it. Prepare your account with your lawyer before any interview.

From a former police investigator's perspective

A "your name came up" message usually means one of two things: your friend named you, or your name appears in his chats near words that matter. Investigators send the voluntary request first because most people come in and talk, and a positive test plus a statement closes the file. What they are weighing about you is narrow — was there use in Korea, and is there evidence of it beyond proximity. An unrepresented foreigner who says "only before I came" and then tests positive on hair has handed them a timing dispute they will resolve against him. The same person, represented, with the dates documented, is a file that often closes with nothing.

You have six weeks, which is enough if you use the first one well. Reach us by text consultation or at +82-2-522-3959 before you reply to that message.

— MEGA X Law Firm Korea, Criminal Defense Team