A laptop containing the details of a number of children attending speech and language therapy services by the Health Service Executive (HSE) in Donegal has been stolen.
It has emerged the laptop was taken from the boot of a staff member's car.
Gardaí have launched an investigation.
This week a number of parents and guardians received letters dated November 7th, informing them of the theft.
The laptop contained a caseload register - which had the names, age groups, schools, addresses and phone numbers of a number of children.
The Data Protection Commissioner has instructed the service manager in the county to inform the parents of this.
The theft happened approximately 100 miles from the county - so the letter concludes that there is little likelihood of local access to the information.
The HSE has apologised for the breach and says it is taking steps to prevent any similar incident.