10/23/2015 05:18 EDT | Updated 10/23/2016 01:12 EDT

Telecommunications firm Talk Talk says 4 million customers' data at risk from hacking attack

LONDON — Phone and Internet service provider Talk Talk says private data from its 4 million British customers may have been compromised in a "significant and sustained" cyberattack on its website.

Chief Executive Dido Harding said Friday that "there is a risk that all of our customers' personal data has been accessed," including credit card and bank details.

London's Metropolitan Police says its cybercrime unit is investigating "an allegation of data theft from a telecommunications website" reported on Wednesday.

Talk Talk has acknowledged that it realized it was under attack on Wednesday. It has been criticized for not telling customers for more than a day.

Talk Talk provides mobile phone and broadband Internet services.

The Associated Press