Hi Sarond,
DBMS flag has been turned off and I have completed a system reset. I have found that most of the forms have been cleared but the main one I was after (users and service configuration) still has all users listed.
This controller was used in a part of a cluster of controllers over multiple sites and as such, there are still 900+ users... like I said before, not too keen on deleting each one by one. Any further info regarding this would be great.
Cheers, Justin