Russian police freed 30 Vietnamese laborers who were forced to work at an underground garment factory without pay, Prague-based newswire RFE/RL reported on Friday.
They also arrested two Vietnamese working as guards at the factory in Yegoryevsk, around 100 kilometers east of Moscow, and an Armenian who directed operations at the facility.
The laborers who were hired in Vietnam by a criminal group had their passports taken away when they arrived in Russia, the newswire quoted Russian Interior Ministry as saying.
Some of the workers were severely punished for trying to escape from the factory, according to RFE/RL.
The report did not mention when the workers had gone to Russia.
Sources said the employers paid nearly 40,000 rubles (US$1,350) each to bring the workers to Russia, Vietnamese newspaper Nguoi Lao Dong reported.
Russian authorities are continuing their investigation of the incident.