Abstract: Controller for retrofit connection to a pre-installed door entry system of an area having a communal entrance secured by a communal door having a first electrically operated lock and a non-communal internal region secured by an internal door having a second electrically operated lock, the door entry system comprising a door panel associated with the communal entrance and an entry phone located within the internal region; the controller being connectable to existing circuitry of the entry phone to be able to receive a request for entry into the internal region from the door panel; and transmit an electrical signal to the entry phone to unlock the first and second electrically operated locks. The controller comprises a detector; a verifier; and a lock controller arranged to generate the signals to control the entry phone to unlock the first and second electrically operated locks when the right of access has been verified.