The five members of the ring allegedly sought out people with financial problems who were willing to sell their kidneys for between $6,000 and $20,000.
Prosecutors say those arrested are part of a criminal network that manipulated board member elections in favor of people who facilitated loans to certain cooperatives.
On Monday, Costa Rican prosecutors announced they are launching an investigation of real estate group Homes Grupo Inmobilario for various developments in the Central Valley.
