TAIPEI (Taiwan News) — Police acting on a tip-off have confiscated NT$1 billion (US$32 million) worth of illegal drugs from an operation out of New Taipei’s Xizhi District and the east coast county of Yilan.

Police said that a 22-year-old man named Zhou (周) headed the drug manufacturing operation and set up multiple production sites to manufacture mephedrone, a stimulant that is commonly referred to in Taiwan by the street name “meow meow,” per LTN. Police seized 50 kilograms of finished mephedrone, and over 1,500 kg of ingredients, as well as 280 kg of marijuana that had been smuggled in to Taiwan from overseas.

Mephedrone is used to make “coffee bags,” a common street drug in Taiwan that is made by adding a mixture of drugs to instant coffee. The recreational drug is often found at nightclubs and has become increasingly popular in Taiwan, though it is not without risks.

Often a combination of multiple different intoxicants, users can not always be sure what they are ingesting when buying from the black market. The Criminal Investigation Bureau said many types of drugs have been found in coffee bags, from mephedrone, to ketamine, and MMA (an MDMA substitute).

Despite ongoing police investigations into marijuana production, a protest in support of the decriminalization of cannabis use in Taiwan took place on April 15. The Ministry of Justice said authorities will continue their campaign against marijuana because of the health risks.