A laptop containing the details of a number of children attending HSE Speech and Language Therapy services 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.
It is being reported that the parents and guardians of the children attending the services in Donegal received letters, dated November 7, from the HSE this week informing them of the theft.
The laptop included a caseload register which had the names, age group, 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 it.
The theft apparently happened around 100 miles from the county and there is little likelihood, says the letter, of local access to the information.
The HSE is apologising for the breach and says steps are being taken to prevent any similar occurrence.