NEW YORK (CNN) -- Real estate developer and political fund-raiser Charles Kushner of Livingston, New Jersey, was charged by federal prosecutors Tuesday with conspiracy, obstruction of justice and interstate promotion of prostitution.The charges were announced by U.S. Attorney Christopher J. Christie for New Jersey.In February 2003, Christie's office began investigating Kushner for alleged violation of federal tax and fraud statutes and for purported violation of federal campaign contribution laws.According to the indictment, two of the cooperating witnesses in the investigation -- a married couple described as close relatives of Kushner -- provided information against him to federal investigators.The indictment alleges...