Employment Law Questions? Ask an Employment Lawyer.
I am sorry to read about your difficulties.
Unfortunately, based on the information that you have provided on your post here, I do not see any remedy in your case. It would be very difficult for you to prove that the investigation was delayed to deny you the opportunity for promotion.
As for the dissemination of the information that you were being investigated to the parties who were not part of the investigation, your privacy was violated. You can file complaint with the department in your agency that handles employee grievances to look into the matter. The investigation was supposed to be private and not to be broadcast to the general population of employees. Nevertheless, you would not have claim for defamation of character if these employees were not told the nature of the investigation, which then concluded in your favor because the allegations were unfounded.
Oh, no. You are still on topic and thank for you for the additional information.
You need to contact the agency that has oversight responsibilities of your agency about the false reports regarding punishment for those who made the initial false reports. You may also take the matter to the prosecutor's office to see if charges could be brought.
You need to make a formal demand for the complete copy of of the investigative report. If your request is ignored or denied. you need to contact the agency with oversight responsibilities over your agency. You may as a last resort file lawsuit to get the information.