The personal details of 37,000 Eir customers have been affected by a data breach, the telecommunications company has said.

In a statement, Eir said an unencrypted laptop was stolen offsite. The company said the data consists of names, email addresses, phone numbers and Eir account numbers. It said no financial data was stored on the laptop.

Eir said the breach was reported immediately to the Data Protection Commissioner and to gardaí and that there is no evidence at this time that the data at risk has been used by a third party.

“Eir treats privacy and protection of all data extremely seriously and our policy is that all company laptops should be encrypted as well as a password protected,” it said.

“In this case the laptop had been decrypted by a faulty security update the previous working day, which had affected a subset of our laptops and was subsequently resolved.”

Eir said it has initiated a programme to contact affected customers.