Six persons have been detained on suspicion of running a fraud via Internet Web pages. The suspects live in San José, Heredia and Guanacaste.
The Judicial Investigating Organization said it had nine complaints against the group.
The individuals are accused of offering for sale in online ads motorcycles and quadracycles and vehicle repair parts and then seeking payment in advance. The vehicles or parts never were delivered, said agents.
During the arrests Tuesday agents said they found nine firearms and a kilo of marijuana.