Officers carried out simultaneous checks at four spa and massage establishments along Bui Vien, De Tham and Pham Ngu Lao streets in the city center.
During the inspections, police discovered several pairs engaged in paid sexual activities and seized documents, account books and cash believed to be linked to the illegal operations. Foreign clients were among those found at the scene.
Police detained a 54-year-old Vietnamese woman identified as Phuong along with several others to investigate alleged prostitution-related offenses on Jan. 12.
Investigators said Phuong was operating multiple spas under the guise of beauty and massage services, organizing prostitution through a structured system that included managers, cashiers, ticket collection, and both cash and bank-transfer payments.
Police are continuing to investigate the case and clarify the roles of those involved.