Telstra has responded after accidentally publishing the details of unlisted customers online.

Telstra has disclosed a privacy breach in which over 130,000 customers’ details were mistakenly published online via Directory Assistance and the White Pages when they should have been unlisted.

Telstra’s chief financial officer Michael Ackland says the company is “in the process” of notifying the impacted customers and removing their listings.

He claimed that “a misalignment of the databases used to provide” Directory Assistance and the White Pages led to the mistake.

The accidentally released data included “customers’ names, numbers and addresses”.

The telco says “no cyber activity was involved” in the privacy breach.

The revelation comes about a year after Telstra was fined $2.5 million for failing to upload information about whether over 115,000 customers wanted an unlisted or silent phone number to the integrated public number database (IPND).