If your employer willfully lies to a future potential employer about the reasons for your termination, then you MAY have a case against your former employer. If the employer has reason to believe that what they are saying is true, then you won't have any basis to pursue a claim against the company, and according to your posting, there are other employees who accused you of these things, giving your former employer reason to think they happened.
Of course, right now, the entire issue is moot. Many employers refuse to provide details about termination to potential employers to avoid this entire issue. If it does become a problem, talk to an attorney then.
This answer is provided for guidance only. DO NOT rely on it as legal advice. We DO NOT have an attorney-client relationship. You should contact an attorney in your area for a one-on-one consultation before pursuing any action or making any decisions.