"A 17-year-old male has been arrested as part of the investigation into a cyber security incident affecting Transport for London (TfL).
The teenager was detained in Walsall on suspicion of Computer Misuse Act offences in relation to the attack, which was launched on TfL on 1 September.
He has been questioned by officers from the National Crime Agency (NCA) and has been bailed.
TfL runs the capital’s public transport network, including buses and the Tube.
It is understood some customer data was compromised, including customer names and contact details.
Some Oyster card refund data may also have been accessed. This could include bank account numbers and sort codes of around 5,000 customers.
The NCA has said it is working alongside TfL and the National Cyber Security Centre to manage the incident and minimise risk to customers…"