washington democratic u.s. senator wednesday urge fbi investigate whether billionaire investor carl icahn break law call biofuels policies would benefit investments serve adviser president donald trump senator tammy duckworth say icahn guidance trump federal biofuel program may create conflict interest oil refine company cvr energy inc cvi.n 82 percent stake appear mr. icahn potentially violate principal conflict interest statute participate government matter affect financial interest say duckworth ethanol-producing illinois letter fbi copy see reuters duckworth say would set dangerous precedent fbi turn blind eye suspicious activity icahn serve special adviser president regulatory reform icahn end adviser role aug. 18 face criticism policy recommendations could benefit investments icahn one loud critics federal biofuels program call renewable fuel standard trump advisor urge administration change standard oil refiners would free blend biofuels ethanol gasoline move enact would shift responsibility biofuels fuel supply chain save refiners hundreds millions dollars year jesse lynn general counsel icahn say email statement say numerous time white house confirm mr. icahn point employee policymaking role trump administration fbi immediately respond request comment letter u.s. senator ask fbi probe icahn biofuels push