German telecom major T-mobile has finally confessed that it has lost data on 17 million subscribers, an admission that could seriously affect its business.

The theft took place back in 2006 but the company has only now admitted the incident. Data on the disk included customers' personal details like name, date of birth, address and mobile phone number, and in some cases the customers' e-mail addresses. But the company insisted that that no banking details were lost.

T-mobile is now trying to reassure subscribers, and says that it has been closely working with German detectives to track down the miscreants and ensure that subscribers won’t be affected. Managing director, Philipp Humm said that the company was aware that the data was being "once more used to the detriment of our clients."

Company spokesperson Frank Domagala said, "According to our information, even though these details have been put up for sale on the black market, there has not been a buyer.”

The company has not yet said how the theft occurred. X