WASHINGTON (Reuters) - Three Democratic lawmakers questioned the White House on Wednesday over its handling of U.S. President Donald Trump’s son-in-law’s potential conflicts of interest now that he is serving as an official adviser.

U.S. President Donald Trump and his senior advisor Jared Kushner arrive for a meeting with manufacturing CEOs at the White House in Washington, DC, U.S. February 23, 2017. REUTERS/Kevin Lamarque

Jared Kushner, a real estate developer who advised Trump during the presidential campaign, was cleared by the U.S. Department of Justice in January to serve as a White House senior adviser. Kushner, who is married to Trump’s eldest daughter, Ivanka, has been given a wide range of domestic and foreign policy responsibilities, including working on a Middle East peace deal.

In a letter to Deputy White House Counsel Stefan Passantino, Democratic Senators Elizabeth Warren and Tom Carper expressed concern over media reports that Kushner is maintaining some business interests, and asked how the White House plans to comply with laws that prohibit federal officials from profiting by government work.

“Neither the White House nor Mr. Kushner’s attorneys, however, has confirmed which financial assets Mr. Kushner still controls,” making oversight “impossible,” they wrote with U.S. Representative Elijah Cummings, the senior Democrat on the Committee on Oversight and Government Reform in the House of Representatives.

They also said the White House, unlike previous administrations, is not posting ethics-pledge waivers on its websites, adding that the public should know the issues from which Kushner must recuse himself.

The White House had no immediate comment on the letter.

A lawyer for Kushner, Jamie Gorelick, said in a statement: “Mr. Kushner is fully complying with the ethics rules, removing himself from active participation in his prior businesses, divesting of substantial assets and recusing himself where appropriate in light of interests that he is not divesting.”

Before Trump took office on Jan. 20, Gorelick said her client would leave his family’s company, divest substantial assets and recuse himself from matters that could affect his financial interests, Bloomberg reported.

Public interest journalism site ProPublica, citing documents submitted to the U.S. Office of Government Ethics, reported in February that Kushner had divested some assets but was keeping other holdings linked to privately held Kushner Companies.

In authorizing Kushner’s appointment, the Justice Department ruled that Trump, as president, has special hiring authority that exempts White House positions from laws barring the president from naming a relative to lead a federal agency.

The Democratic lawmakers called on the White House for details on what holdings Kushner maintains, a list of issues he will recuse himself from, and copies of any ethics waivers.

They also raised questions about holdings belonging to his wife, who established a clothing and jewelry line, and whether that would lead Kushner to recuse himself from any issues.

Trump himself has said he would maintain ownership of his global business empire but would hand off control to his two oldest sons while president.