A second teenage boy has been arrested in connection with the cyber attack on TalkTalk.
A 16-year old boy from West London was arrested by the Metropolitan Police Cyber Crime Unit investigating the hack.
Earlier this week, a 15-year old from Northern Ireland was released on bail after being arrested in connection with the cyber attack.
TalkTalk's website was hacked last week, putting its four million customers' details at risk. But the telecoms giant later said the attack was "smaller" than first thought.