WASHINGTON (Reuters) - Three Democratic lawmakers sent a letter to the president of Kushner Companies on Thursday seeking information related to concerns that the real estate firm has exploited Jared Kushner’s role as a White House adviser to attract investment through a federal immigration program.

FILE PHOTO - White House senior advisor Jared Kushner arrives to join U.S. President Donald Trump and the rest of the U.S. delegation to meet with Saudi Arabia's King Salman bin Abdulaziz Al Saud at the Royal Court in Riyadh, Saudi Arabia May 20, 2017. REUTERS/Jonathan Ernst/File Photo

Jared Kushner, the son-in-law of President Donald Trump and one of his top advisers, early this year stepped down as chief executive officer of his family’s real estate company.

Senator Patrick Leahy and Representatives John Conyers and Zoe Lofgren, in the nine-page letter dated Thursday and sent to Kushner Companies President Laurent Morali, asked for details about the company’s controversial May road show in China, where the developer offered investors a chance to get U.S. visas under the EB-5 program if they put money in a project in New Jersey, One Journal Square.

The letter, which was released publicly, also asked Kushner Companies what steps it has taken to ensure its affiliates do not exploit Jared Kushner’s White House role when wooing investors in the future.

The lawmakers cited a May 12 Reuters report that a Chinese immigration agency promoting the Kushner Companies project had touted Kushner’s White House connections to assure potential investors that the One Journal Square project would succeed and investors would receive green cards.

Such guarantees are prohibited by the rules of the EB-5 program, which grants foreigners a U.S. green card in exchange for investing $500,000 or more in development projects in low-employment areas of the United States.

Kushner Companies did not immediately return calls for comment.

Kushner Companies had apologized for Nicole Kushner Meyer’s reference to her brother, Jared Kushner, when pitching One Journal Square in China in May.

The letter by the three Democrats follows a call by the Republican chairman of the Senate Judiciary Committee, Chuck Grassley, last week for a probe into “potentially fraudulent statements and misrepresentations” made by companies promoting investment in the One Journal Square project.

Leahy, Conyers, and Lofgren - all members of the House or Senate Judiciary Committees - noted in their letter that they have worked with Republican committee members since 2015 to improve the EB-5 program by enacting tougher anti-fraud measures.

Jared Kushner used to be closely involved with groups that lobbied against those reform efforts, according to the letter, including one firm that is marketing the One Journal Square project.

The Democratic lawmakers’ letter asked if Kushner Companies had engaged in any lobbying related to EB-5 program reforms or discussed the program with Kushner since Trump took office in January.