Mobile phone tracking devices designed to allow parents to monitor their children’s whereabouts could be illegal.
The Office of the Ombudsman for Data Protection is warning that children's rights could be violated by the service.
Under data protection legislation, people must consent to having the tracking device on their phones before it is installed.
It is feared that children under the age of 16 may not understand the issues involved.
Concern is being expressed that many children will be pressured into consenting to the service by their parents.