Employer threatening to file report with educational institute

I was an intern under a person working at a reputed government research institute. I worked on a research project and my employer, in order to push me out of the same so as to prevent me from getting any credit, falsely accused me of academic dishonesty. I clearly stated my case and proved that it wasn't such a case on my part but he just denied listening to any replies. Now, in order to pressurize me from pursuing it further, he is threatening to report it to my educational institute and inform about it to any of my future employers. In case he proceeds, I will be facing unnecessary trouble at my institute until my case is heard and resolved. What are my options ?