Public records and shell companies shield the investor’s identity. In the United States, federal prosecutors are investigating whether representatives of his firm bribed government officials in Guinea to secure a multibillion-dollar mining concession. The Steinmetz partnership with Kushner underscores the mystery behind his family’s multibillion-dollar business and its potential for conflicts with his role as perhaps the second-most powerful man in the White House, behind only his father-in-law, President Trump. Last month, his company said it had ended talks with Anbang Insurance Group, a Chinese financial firm linked to leading members of the ruling Communist Party. Even as Kushner’s company maintains extensive business ties to Israel, as a top White House adviser, he has been charged with leading U.S.