Democratic lawmakers are raising new concerns about Carl Icahn and whether the billionaire is using his role as an adviser to the White House to bolster his personal investments.

Senators Elizabeth Warren and Sheldon Whitehouse are asking financial regulators questions about whether Icahn is communicating with officials about American International Group Inc. and the strict rules that were imposed on the company after the financial crisis. In a letter to Treasury Secretary Steven Mnuchin, the Democrats ask if the billionaire has had any contact with him or other regulators about whether AIG should be freed from its designation as a systemically important financial institution, a label that can subject it to tough government oversight.

“There is ample evidence that Mr. Icahn will not hesitate to discuss and advocate for positions that benefit him personally," the senators wrote in a letter Thursday. “We write to seek assurances that Mr. Icahn has not provided input on or received information," on a pending decision of AIG’s SIFI status.

Icahn is one of the largest investors in AIG and said in 2015 that the insurer should split into three companies to avoid the “ tax on size” imposed by regulators. After the departure this year of Chief Executive Officer Peter Hancock, the activist eased off his demands that AIG slim down. Icahn wants to give new CEO Brian Duperreault a chance to improve the company’s profitability, people familiar with the matter told Bloomberg last month.

Advising Trump

Warren, of Massachusetts, has previously asked regulators to look into Icahn’s role as a special adviser to President Donald Trump, arguing that the arrangement is fraught with potential conflicts considering Icahn’s extensive investment portfolio.

Icahn, who was named to the unpaid role consulting on regulations in December, has argued that Trump is under no obligation to take his suggestions. An attempt to reach a representative for Icahn wasn’t immediately successful Thursday. The Treasury Department didn’t immediately respond to a message seeking comment.

The lawmakers are reaching out to Mnuchin in his capacity as chairman of the Financial Stability Oversight Council, a panel of regulators that has authority to declare firms as SIFIs. While big lenders such as JPMorgan Chase & Co. automatically received the risk label, AIG is one of just two non-banks that still remain as SIFIs.

This article was provided by Bloomberg News.