A DERRY based broadband company has apologised after the details of thousands of customers appeared on an online notice board.
Bluebox Broadband said it had contacted all those affected by the breach, estimaed at 3,000, whose names, email addresses and phone numbers were leaked online.
It comes just a month after TalkTalk was affected by a "significant breach" of banking details and personal information of its customers after its website was attacked.
In existence for a decade, Bluebox states on its website that it aims to provide "faster, smarter broadband to areas of Northern Ireland and Donegal that most providers can’t get to."
The Information Commissioner's Office, which investigates breaches of data protection, said it was aware of the incident and was making inquiries.
Bluebox said the information had come from a server used to store details of people registering an online interest in the firm's services.
Scott McClelland, managing director of the firm, said the server had been immediately shut down and the PSNI informed.
The details have been removed from the website on which they were posted.
Mr McClelland told the BBC: "At Bluebox we have always taken security very seriously and this incident is the first time anything like this has ever occurred in the 10 years since we began providing internet services."
He added: "While no significant customer information has been exposed, we will be working with independent experts to learn lessons and take all steps necessary to prevent anything like this happening in the future."
