A/P P.O. Price VS invoice price

We had a situation last week where we found an invoice price had been costed
incorrectly and didn't match the original PO price. Obviously this affected
our cost after roll ups etc. I was asked how this could be caught in the
future. It was mentioned that an employee no longer with the company used
to run a report that displayed discrepancies such as this. Unfortunately
nobody could remember which report it was. Any ideas?



Thanks,



Jeff