Dear Ranjit,
first thing that you need to put into consideration in supervising HR is to sequence the correct process in providing decisions and evaluations to your people particularly for those employees involving commiting any violations. Giving suspension to your employees without following due process is against on your labor laws.
First thing that you need to do is to send a notice of violation to the employee and with that you are giving him/her the chance to explain his/her side through writing explaination. In our company we give them 3 days due date to reply. No reply means, the employee waived or agrees for whatever the decision and sanction of your labors relations department that will be imposed to him/her.
Second, after calling his attention that your office acknowledge his response.. this is the best time for personal interview (inquiry), there should be a representative from the labor union.
Lastly, the decision of the management based on the inquiry and collective bargaining.
Hope this helps.