Russian investigators on Thursday opened a criminal probe into a rehabilitation centre in Siberia where alcoholics and drug addicts were handcuffed to beds, charging the facility's management with unlawful imprisonment.
Special forces and national guard officers in flack jackets raided the centre in country's the latest crackdown on private clinics promising to cure addicts with brutal "cold turkey" methods.
The facility in the Omsk region some 2,200 kilometres (1,400 miles) east of Moscow isolated addicts from society and prevented them walking around freely, the Investigative Committee, which probes high-profile cases, said in a statement.
"Staff used locks, metal bars on windows, handcuffs to chain people to beds and also dumbbells that were attacked to patients' legs."
Patients who disobeyed rules were "harshly beaten up," investigators said.
The centre's chief and his deputy face charges of unlawful imprisonment and risk prison terms of up to five years. Investigators said the head of the centre had no medical qualification or licence to operate.
One of Russia's first "cold turkey" rehab facilities was founded in the late 1990s by a former mayor of the Urals city of Yekaterinburg to counter the drug addiction gripping the country.
The centre also handcuffed addicts and has been raided numerous times but has also won praise from some for offering an alternative to state-funded treatment.
Such locked facilities for treating addicts are highly risky and several have caught fire.
In 2016, 12 people died when a fire swept through a rehab centre with barred windows in central Russia.
Russia controversially opposes supplying heroin addicts with the safer substitute methadone, which is internationally seen as effective.