U.S. Attorney for the Southern District of New York Preet Bharara sent a letter to the International Consortium of Investigative Journalists asking for information that could assist in a new criminal investigation concerning "matters to which the 'Panama Papers' are relevant."

U.S. Senators Elizabeth Warren (D-MA) and Sherrod Brown (D-OH) urged the Treasury Department to investigate whether, through involvement with a Panamanian law firm, U.S. companies and persons may have evaded tax obligations or facilitated money laundering and other illegal activity.