The factory in Noginsk, a town east of Moscow, was raided Wednesday, RIA Novosti reported. Investigators were trying to determine who owns the business and the building.
The employees were living in the factory as well as working there, producing sportswear to be sold with counterfeit labels, investigators said.
The Vietnamese were taken to a local police station.
Notable deaths of 2014 [PHOTOS]
Bus attack in Pakistan kills eight