The PSNI have been using a private security firm to trace Twitter accounts of alleged trolling officers

A private cyber security firm has been involved in a year-long probe into the anonymous Twitter accounts of officers and staff within the Police Service of Northern Ireland allegedly involved in online racist abuse and trolling, it can be revealed.

The firm was hired by the PSNI last year to help trace the identity of the individuals behind a number of Twitter accounts, which also appeared to publish information about ongoing police operations, the Press Association has learned.