> It seems to me that the disappeared funds could have gone to people with access to the system
How could that happen outside of the Post Office? ICL/Fujitsu had remote access to all the remote boxes and could add/amend records without any audit trail and without knowledge of the sub postmasters, but I can't see how they could get money to go into their own pockets unless they entered into a deal with the sub postmaster operating the branch. Hypothetically, they could delete some transactions and then the sub postmaster would have more money in their till than accounted for and could split the proceeds. (I don't think this ever happened).