The crystal-encased chip, which is the size and shape of a grain of rice, is injected into clients' bodies with a syringe.
Xega, based in the central Mexican city of Quererato, designed global positioning systems to track stolen vehicles until a company owner was kidnapped in broad daylight in 2001. Frustrated by his powerlessness to call for help, the company adapted the technology to track stolen people.
Most people get the chips injected into their arms between the skin and muscle where they cannot be seen. Customers who fear they are being kidnapped press a panic button on an external device to alert Xega, which then calls the police.
Outside of Mexico, U.S. company VeriChip Corp uses similar radio-wave technology to identify patients in critical condition at hospitals or find elderly people who wander away from their homes.
Xega sees kidnapping as a growth industry and is planning to expand its services next year to Brazil, Colombia and Venezuela.