A teenager from Antrim has been arrested in connection with the crime. The 15-year-old was taken into custody after an investigation by the Metropolitan Police cyber crime Unit, the PSNI and the British National Crime Agency. The boy was detained after the NCA conducted a raid on Monday in Northern Ireland. According to the police he was questioned over the attack and a search of the premises by officers is ongoing. However, the police have released the teenager on bail. Meanwhile, TalkTalk shares have tanked more than a tenth of the value of TalkTalk on London Stock Exchange on Monday as traders reacted to the breach, the third cyber attack in eight months on the firm in which customers’ data have been stolen. The company has said it is unsure how many of its four million customers in Britain were affected, but said that information including customer names, addresses and bank details could be at risk.