SHENYANG - Police in the northeastern Chinese city of Shenyang said that they have arrested 20 people for distributing an addictive cough syrup.

More than 6,700 bottles of a compound containing codeine phosphate, a potentially addictive prescription drug, have been seized, according to Shenyang police on Thursday.

The syrup is manufactured in Shenyang.

Preliminary investigation showed that an employee from a retailer in north China's Hebei Province sold the cough syrup for profit by falsifying orders from clients, most of which are rural medical institutions.

Codeine, which is extracted from opium or synthesized from morphine, can lead to drug addiction. Using codeine-based drugs in excessive amounts can also cause problems including stomach ulcers and liver damage.

Substances containing codeine are strictly controlled by China.