A 21-year-old man has been arrested as part of a cyber crime investigation into computer hacking at children's electronic toy maker VTech.
The suspect was detained in Bracknell, Berkshire, on Tuesday morning, the South East Regional Organised Crime Unit (Serocu) said in a statement.
He was held on suspicion of "unauthorised access to computer to facilitate the commission of an offence" and of "causing a computer to perform a function to secure/enable unauthorised access to a program/data".
A number of electronic items were seized by investigators.
Last month VTech had customer data which was housed on its Learning Lodge app store database hacked.
Learning Lodge allows customers to download apps, learning games, e-books and other educational content to their VTech products.
Its database contains general user profile information including names, email addresses, encrypted passwords, secret questions and answers for password retrieval, IP addresses, mailing addresses and download histories.
Following the breach, VTech said its customer database does not contain any credit card information and VTech does not process or store customer credit card data on the Learning Lodge website, or hold personal ID.
Craig Jones, head of the cyber crime unit at Serocu, said: "Cyber criminality is affecting more and more businesses around the world and we continue to work with our partners to thoroughly investigate often very complex cases.
"We are still at the early stages of the investigation and there is still much work to be done. We will continue to work closely with our partners to identify those who commit offences and hold them to account.
"We are pursuing cyber criminals using the latest technology and working with businesses and academia to further develop specialist investigative capabilities to protect and reduce the risk to the public.
"Cyber crime is an issue which has no boundaries and affects people on a local, regional and global level."