The prosecution will set up specialized teams at its regional offices in major cities to investigate drug-related crimes.

According to the Supreme Prosecutors' Office(SPO) on Friday, four teams will begin operations in central Seoul, Incheon, Busan and Gwangju.

A prosecutor will be in charge of each team comprising up to 15 investigators. 

Officials from the state intelligence and customs agencies, the food and drug ministry, and the state broadcasting and communications regulator will also join the investigation. 

The teams will focus on tracing large-scale drug trafficking, illegal distribution of narcotic substances intended for medicinal purposes, and online distribution through the dark web.

A nation is generally considered "drug-free" when there are 20 or fewer offenders for every 100-thousand people each year. South Korea should post less than ten-thousand to meet that standard.