Bank a/c for convenience

If it is a purely business account for his employer through which only official business is transacted, then there is no need for the manager to disclose this account.  After all, only the account operates in his name whereas all the transactions are for the company.  May be he can open the account with the title "AAA, Manager" so as to clear the air.  If the employer does not show the same in his return, then there is a problem as th employer can always say that the Manager had done it on his own and the employer was not aware of the account.  It all boils down to the facts.  It may also be hard for the Manager to convince the IT Department that all the transactions were only for the purpose of his company and not himself.  Of course if even a single personal transaction is found in the account, then he will be in trouble.