This to me sounds like a case of defamation because he is spreading rumors and lies about you. Defamation is basically a false and defamatory statement, published to a third party, that causes harm (usually a lessened reputation in the community, lost business opportunity, or other harms as the facts dictate.)
Although I don't know the full extent of what was the supposed defamatory statement, run the alleged statements through that analysis to see if it fits.
If it does, then the other party may have some defenses. Here are the typical defenses in a defamation case:
(1) Legislative Privilege - Meaning the statement was made in a legislative proceeding
(2) Judicial Privilege - any participant in a judicial proceeding the absolute privilege to utter defamatory statements
(3) Executive Privilege - privilege affords an absolute privilege to high ranking executive officers of state and federal governments when acting within the scope of their discretionary duties
(4) Domestic Privilege - affords a spouse the absolute privilege to make defamatory statements about a third person to their spouse.
(5) Truth - if the statements you made were true, then this is a defense as well
(6) Opinion - courts have ruled that the opinion defense is one where if you provide your opinion, then a defamation charge will not stand.
It is probable that none of those six apply.
What other questions did you have for me today that I can help you out with:-)?