Customs officials on Russia’s Sakhalin Island are investigating a Korean woman on charges of drug possession after they found massive amounts of sleeping pills and stomach medicine in the woman’s luggage.

The woman, identified only by her surname Shim, was apprehended by customs officials while trying to enter Sakhalin from Seoul in August. At the time, customs officials confiscated 160 packs of medicine from Shim’s luggage, saying the medicine needed to undergo analysis. The officials said that traces of narcotics have been found in the medicine and reportedly notified Seoul that they will conduct further investigations into the matter.

Shim complained of injustice to the South Korean diplomatic office in Sakhalin. The office has since issued a protest on the matter to Russia’s Foreign Ministry.