1. Promotion can not be demanded, it is awarded,
2. However, you should have been considered for the interview for promotion,
3. I know about a case in a Bangalore based PSU where the officers charged by CBI were given promotion but the Approver, though interviewed for promotion, was not promoted,
4. In the above case senior Managers were involved with the scam who decided about the npromotions,
5. In your case the authority could have kept your promotion order in sealed envelope till the case is disposed of, as per practice.