Answer:
Tort.
Explanation:
There are no facts given that would suggest a breach of contract (though with certain facts, that could be the case).
With facts given, this would be a Tort, defined as "a wrongful act or an infringement of a right (other than under contract) leading to civil legal liability."
The former business partner, if the allegations are found true, is in violation of intellectual property laws, theft and possibly other legal theories which may be applicable given additional facts.
There is no discussion of a contract; this is not a criminal offense; and there is no evidence of a prior judgment to be adjudicated.
