Government work has paid off handsomely for billionaire Carl Icahn.

CVR Energy Inc., his oil refining company, saved about $60 million in the first quarter because of expectations that the federal government will ease a regulation involving renewable fuels, securities filings show.

It’s much more than a lucky break. As a “special regulatory adviser” to President Donald Trump, Icahn himself has been advocating the kind of relief that will benefit his company.

Icahn’s cost savings show how the Trump administration has let officials’ outside business interests influence policy decisions. Richard Painter, a University of Minnesota Law School professor and White House ethics counsel under President George W. Bush, calls Icahn’s role “a clear conflict of interest.”

Even before the magnitude of Icahn’s gain was known, a group of U.S. Democratic lawmakers sent a letter to regulators urging them to investigate whether Icahn used his role as adviser to gain unfair