TalkTalk hacking crisis deepens as more details emerge

Telecoms giant receives ransom demand and reveals stolen data of up to 4 million customers may not have been encrypted

TalkTalk is facing increasing criticism after belatedly admitting it was the victim of a "significant and sustained" cyber-attack that has led to the theft of the credit card and bank details of up to 4 million customers.

The telecoms giant warned that the stolen customer data may not have been securely encrypted and that it had received a ransom demand from someone who claimed to have carried out the corporate hack.