A 17-year-old boy has been arrested in Walsall as part of the investigation into a cyber security incident affecting Transport for London (TfL), the National Crime Agency said.

The teenager was detained on suspicion of Computer Misuse Act offences in relation to the attack, which was launched on TfL on September 1.

The boy, who was arrested on September 5, was questioned by NCA officers and bailed.

It comes as TfL said some customer data was accessed in the cyber attack.

TfL has been investigating the incident, which was identified on September 1, alongside the NCA and said some customer names and contact details had been compromised.

Some Oyster card refund data may also have been accessed in the cyber attack which could include bank account details.