Dear Pravin Mhaske,
You say that the driver was involved in the fraudulent activity. Is the driver on the rolls of your company or he is a contract employee?
Anyway, fraud has to be investigated properly. Therefore, let the management of your company order the domestic enquiry. Let the matter be investigated impartially. Please note that the focus of the enquiry should not be on the person but on the incident.
By conducting the enquiry, we understand the loophole in the system. Those who know how to make deceitful pretences take benefit of the loopholes. Therefore, to avoid the repetition of the incidents, plugging those loopholes is important.
Finally, about the issue of the warning letter. If the employee has been involved in the fraud, then it is serious misconduct, and the guilty cannot be let off with just a warning letter.
Thanks,
Dinesh Divekar