Although the ring was based in La Carpio, agents said they believe that those involved in the ring sent youngsters out to solicit business on the south side of downtown San José, according to a bulletin from the Judicial Investigating Organization.
A judicial spokesperson said Friday that police had rescued four underage women from the ring, and said that these women received minimum pay but did not specify how much that was.
Judicial officials identified the three siblings in custody as Blanca, Hellen and Edwin Hernández. They are in their 20s.
The 32-year-old taxi driver was identified only by the last name of Bejarano.
Police began investigating several months ago after they were tipped off about the ring.
The bulletin said that the trio recruited underage women between the ages of 10 and 17 in the slum of La Carpio in La Uruca. It added that agents believe that the three persons preyed on vulnerable young women, deceived them and forced them to live in their house with them.
Investigators said that these women were rented to clients at any and all times of the day as customers were recruited.
Officials said that these are classic tactics used in these situations. They said that keeping the girls in the house while intimidating them and threatening them and their families with physical harm keeps the girls both submissive and dependent on their captors.
The report said that the the operators of the prostitution ring looked for clients along Avenidas 14 and 16 in San José, offering prices between 25,000 and 50,000 colons. The three suspects were arrested at their home in La Carpio in a raid there Friday morning.
The taxi driver Bejarano was arrested that same morning at his home in Barrio el Pilar in Guadalupe. Agents said that he is suspected of being the exclusive driver for the ring and knowingly took young women to the homes of clients.
The area in the south side of San José is well known for sex trafficking activities, particularly at night.