If the employee has committed fraud, then he/she deserves punishment. For this, you need to first conduct a domestic enquiry. Allow the employee to defend his/her position. Ensure that the enquiry is not tainted in any way.
If the culpability of the employee is established in the enquiry, then management can dismiss the employee. If the fraud is of a serious nature, such as misappropriation of funds or embezzlement, you may also lodge a police complaint.
Issuing a Service cum Employment Certificate
When issuing the "Service cum Employment Certificate," you can mention the reason for leaving the employment as "Services discontinued on disciplinary grounds." The fraudster cannot present a certificate of this kind to anyone. This is a severe punishment.
Blacklisting Employees
Regarding the question of blacklisting, yes, there are a few websites where you can list the names of employees of this kind. However, doing so may be seen as vindictive. The issue was between you and the employee. By terminating the employee, you have taken action, and the matter should end there. I do not recommend involving a third party.
I say this because fraud exists on both sides, with employees and employers. There are websites that mention only the names of fraudulent employees, but why not fraudulent employers? In this forum, numerous posts mention non-payment of salaries, non-payment of gratuity, on-the-spot dismissal, etc. Employers of this kind often escape punishment with impunity.
Listing an ex-employee's name on a website to prevent them from getting future jobs is akin to seeking vengeance repeatedly. They made a mistake for which you have already punished them. However, thinking about punishing them in the future as well is insidious. Let them face their consequences. Allow them a chance to reform.
In the third paragraph above, I mentioned issuing an employment certificate with negative remarks. In fact, I recommend against doing that as well. Simply write the remarks as "normal."
Regards,
Dinesh V Divekar