Authorities in Jeju have discovered a package that they suspect contains ketamine, the 15th such discovery in less than two months.

A coast guard officer found roughly one kilogram wrapped in a green oolong tea bag along the shore of Jocheon-eup at around 2:26 p.m.

Investigators say it resembles the ketamine packets that have repeatedly appeared on Jeju’s coast since late September, and plan to run a field test to confirm its contents.

On Monday, a marine environment volunteer on Udo Island found a silver tea-bag packet later confirmed as ketamine following police analysis.

In total, about 35 kilograms of similar material have been recovered, enough for more than one million individual doses.

The coast guard is working with overseas partners to trace how the drugs entered the surrounding waters.