Unreconciled Cash Balance

Hi

A client runs a pub through a limited company and has poor controls over the cash in the till in that he pays suppliers etc from the till cash. This has resulted in a difference between recorded sales and the cash entering the business (after accounting for credit card payments and receipts from suppliers who were paid in cash). I am assuming that he takes cash out for herself but he denies this. I have indicated to him that if HMRC rock up and audit they will assume the difference is his takings and charge him penalties for unpaid NIC's etc.

However at year end this amount is still unreconciled and needs to be allocated somewhere in the accounts. The previous accountant simply allocated it to 'cash wages paid' but I am reluctant to do that because of NIC's and that.

Any advice as to what I should do? (apart from resigning as the accountant which i am considering)