A 15-year-old boy who was arrested in Co Antrim yesterday as part of the investigation into the alleged theft of data from TalkTalk has been released on bail.
The investigation being conducted by the Britain's Metropolitan Police Cyber Crime Unit, the PSNI and National Crime Agency (NCA) is continuing.
The personal details of up to four million customers may have been stolen in the attack.
Officers are investigating a ransom demand sent to the the phone and broadband provider by someone claiming to be responsible.
The breach is the third in a series of cyber attacks that have affected TalkTalk customers.
In August, the firm revealed its mobile sales site was hit by a "sophisticated and co-ordinated cyber attack" in which personal data was accessed.
In February, customers were warned about scammers who managed to steal thousands of account numbers and names from TalkTalk's computers.
