The Royal Bank of Scotland has admitted that it had kept 4,500 customers in the dark when they sought information about the cash that was lying in their dormant accounts. Now RBS is facing an investigation by the City watchdog after the revelation. The depositors were told that their savings were not held at the bank when in fact they were. RBS, which is still 73%-owned by the British taxpayer, admitted that it had set up the wrong filters on computer software designed to seek out the owners of inactive accounts.