Moscow: Around 12 kg of Gamma hydroxybutyric acid (GHB), also known as "Liquid Ecstasy", has been seized by police in Moscow region, the Federal Customs Service said.
GHB is classified as an illicit drug in many countries. It occurs in small quantities in the human body and is sometimes used as a psychotropic substance in medicine to treat narcolepsy.
The use of the drug, which causes addiction, may lead to negative changes in consciousness and behaviour. Its overdose may be fatal.
A channel to smuggle GHB from China by mail has been blocked, according to customs officials.
Many residents of Moscow region, involved in organising illegal deliveries of psychotropic substances, have been detained, the Customs Service said.
A total of 11.6 kg of the psychotropic substance was seized from them. It is equivalent to 30,000-50,000 drug doses, it said.
If found guilty, the detainees face up to 20 years in prison.