Refunded fraud after year end

A client noticed several fraudulent transactions on bank statement - to various airlines for a material amount. He queried this with his bank, who made enquiries, decided that the transactions were fraudulent and were not my client's fault, and refunded the money. However, the money was only refunded after YE.

Where should these fraudulent entries appear on the accounts? As a debtor, or on the P&L with a corresponding reversal the next year? If so, I assume it would be disallowed for tax relief, rather than tax relief taken, and a corresponding "taxable income" received in the following year?