In a letter (pdf) to the White House on Thursday, the Office of Government Ethics (OGE) warned that a top Trump administration ethics official may have violated the very rules he is required to enforce by allowing billionaire investor Carl Icahn—who has frequently advised President Donald Trump on a variety of issues—to skirt financial disclosure requirements.

"No one has believed for months that this president or his administration had any interest in ethics."

—Noah Bookbinder, Citizens for Responsibility and Ethics in Washington

Concerns of a possible violation were initially raised in a recent letter (pdf) sent to Stefan Passantino, Trump's designated agency ethics official, by five Democratic senators.

The letter—signed by Sens. Elizabeth Warren (D-Mass.), Sheldon Whitehouse (D-R.I.) Thomas Carper (D-DE), Elijah Cummings (D-MD), and Patrick Leahy (D-VT)—noted that the "White House has treated Mr. Icahn as an informal advisor, allowing him to avoid complying with basic standards that apply to other federal employees, such as requirements to disclose conflicts of interest or divest from financial assets that pose potential conflicts."

The senators continued:

As a result, Mr. Icahn has been advising President Trump while simultaneously serving as the Chairman of the Board and majority shareholder of lcahn Enterprises, a "diversified holding company." Ethics watchdogs have called Mr. Icahn's arrangement "the purest definition of a conflict of interest that you can get." Several of us have written to both White House Counsel Don McGahn and Mr. Icahn seeking information on Mr. Icahn's role in the White House and any financial disclosures he has been required to file but have received no response. The White House has not offered any justification for its classification of Mr. Icahn or its decision not to follow these basic ethics procedures for someone advising the President on a broad range of issues.

The letter went on to highlight as particularly alarming the fact that Passantino had worked for Icahn in the past, which "raises obvious conflict of interest questions about his potential role as the official responsible for approving and enforcing Icahn's ethics requirements."

This is the lawyer in charge of ethics for the White House. https://t.co/bjVJcmTZeg — Citizens for Ethics (@CREWcrew) June 29, 2017

The Trump administration, in one headline: White House Asked to Probe Top Ethics Official for Ethics Violations https://t.co/HrYa3p58QG — Adam Smith (@asmith83) June 30, 2017

While the Trump administration has dismissed the senators' concerns as political posturing, OGE director Walter Shaub on Thursday sent a request to White House Counsel Don McGahn to further investigate the matter and offer "a determination as to whether action is needed.

As Bloomberg reported earlier this year, Icahn's stake in the petroleum refiner CVR Energy Inc. soared after he "helped broker a proposal to alter U.S. biofuels policy."

John Wonderlich, executive director of the Sunlight Foundation, called Icahn's relationship with the Trump administration "certainly unethical."

Trump, who campaigned on the promise to "drain the swamp," has repeatedly been criticized for filling the ranks of his administration with corporate lobbyists.

As Common Dreams reported earlier this month, Trump has issued ethics waivers to more than a dozen members of his staff, allowing them to evade central ethics rules ostensibly designed to prevent conflicts of interest.

"The ethics waivers the White House finally released reveal what we already suspected: that this administration is chock full of senior officials working on issues on which they lobbied, meeting with companies in which they have a financial interest, or working closely with former employers," concluded Noah Bookbinder, executive director of Citizens for Responsibility and Ethics in Washington (CREW). "No one has believed for months that this president or his administration had any interest in ethics."