fraud

if some one done case without any reason on our land..we win case.. but we have done any case to charge amount him.. now after 3 year.. he is again doing some problem.. he is showing our land to person . its not his.. if he do some wrong action and take money for our land sale . what we can do… and we have prove he had done fraud in past and sale is land more than he have.. and done fraud where we can complaint againt land fraud… either FIA Deail it . or some other autnority