This Practice Note provides guidance to practitioners representing prosecutors, spouses and defendants in contested proceeds of crime matters involving competing claims under the Matrimonial Causes Act 1973 (ie claims in respect of matrimonial assets where there has been a breakdown of a marriage). It explains why contested matrimonial proceedings create an issue for those working on proceeds of crime matters, the interplay between the criminal and family courts in such cases, how the parties can or should litigate these matters in either the criminal or family courts including which claim takes precedence, steps to bringing or intervening in proceedings and other practical points to consider.