It is only when a charge-memo in a disciplinary proceedings or a charge-sheet in a criminal prosecution is issued to the employee that it can be said that the departmental proceedings/criminal prosecution is initiated against the employee. The sealed cover procedure is to be resorted to only after the charge-memo/charge-sheet is issued. The pendency of preliminary investigation prior to that stage will not be sufficient to enable the authorities to adopt the sealed cover procedure.
Since charge sheet sheet has not been served to you in connection to any inquiry whatsoever, sealed cover procedure couldn't have been resorted to in your case.
Approach the High Court.