One-hundred-thousand Bulldog broadband customers have had their contact details stolen, according to Cable & Wireless, Bulldog's former parent company.
An unnamed third party obtained the details in December 2005, reported The Guardian on Thursday. The newspaper quotes a customer who says that bank account and credit card details were stolen.
Cable & Wireless confirmed that the number of records stolen was "in the region of 100,000", but said there is "absolutely no evidence" that banking details were used illegally. It also confirmed that it had "received a very small number of complaints from customers who had experienced unsolicited and possibly repeat telemarketing calls using contact details that we believe were illegally obtained over two years ago".
Accordibg to the Guardian report, Cable & Wireless declined to reveal the identity of the thief, who is now the subject of legal action that the telco has brought.
Cable & Wireless bought Bulldog in 2004 before it sold the business to Pipex in 2006.