Police said Friday they have arrested and detained five people, including a Korean man with Canadian nationality, suspected of dealing marijuana in two separate drug rings.

Police also booked 31 others, including a 36-year-old college professor from the U.S., for investigation without physical detention for allegedly purchasing the drug from the arrested suspects, the Seoul Metropolitan Police Agency said.

The Canadian national, a underground hip-hop singer working as a native teacher of English, identified only by the initial of his name H, allegedly sold marijuana to fellow English teachers from the U.S. and Canada as well as to an employee of a local industrial conglomerate, the police said.

The suspects are believed to have distributed about 438 grams of Canadian and locally-grown hemp in well-known private English education institutions in Seoul and nearby and southern cities since July last year, according to the police.

They are alleged to have divided roles among themselves to separately and secretly deliver and sell the drug.

Among those arrested or booked was a 31-year-old teacher of English employed by a private institution who allegedly smuggled Canadian hemp into Korea and sold it to fellow teachers, as well as a local college student who is suspected of buying marijuana to re-sell to local Koreans, including an office worker, a used-car dealer and a bar owner.

Alleging widespread marijuana smoking among foreign teachers, the police said the country needs a more thorough system to identify illegal hemp use among native English-speaking teachers here.

“We plan to further broaden our investigation as there are assumed to be more hemp-circulation rings involving native teachers (of English),” a police official said.

Under South Korean law, marijuana users can be sentenced to a maximum of five years in jail or fined up to 50 million won (US$44,500). (Yonhap News)