White House senior adviser Jared Kushner looks at his notes as he speaks to reporters outside the White House in Washington, Monday, July 24, 2017 Associated Press/Alex Brandon Federal prosecutors in New York have reportedly subpoenaed Kushner Cos., the firm belonging to White House senior adviser Jared Kushner, over its use of a controversial visa program the company used to woo Chinese investors to fund a New Jersey development, the Wall Street Journal reported Wednesday.

Citing people familiar with the matter, the Journal reported that the subpoena is regarding the apartment complex One Journal Square in Jersey City, New Jersey.

The complex consists of two 66-floor towers that were financed in part by the EB-5 program, which exchanges US visas for certain types of investments,

The subpoena, which was issued in May, came shortly after it was reported that the company used Kushner's position as President Donald Trump's senior advisor to promote the company and the One Journal Square development to Chinese investors.

Kushner's sister, Nicole Kushner Meyer, mentioned him and used an image of Trump during a promotional event in Beijing advertising the development project. The company was seeking to raise $150 million, or about 15% of the funding for the development, through the EB-5 visa program, Reuters reported in May. The company later issued an apology for including Kushner's name in pitching the project to investors.

Federal prosecutors included a demand for emails in its document request. But it's unclear what sorts of alleged violations are being investigated.

Kushner Cos. general counsel Emily Wolf told the Journal that the firm is cooperating with legal requests for information.

"Kushner Companies utilized the program, fully complied with its rules and regulations and did nothing improper," Wolf said.

Online promotions posted on Chinese websites also touted Kushner's role in the EB-5 program and the One Journal Square project.

"Even some members of Trump's family have participated in the growth of the EB-5 program," one webpage from the Chinese company Qiaowai said. "The lead developer on the now-completed project was Kushner Companies which is linked to Trump's son-in-law, Jared Kushner."

Although Kushner resigned from his position at the company prior to joining the White House, he reportedly remains invested in the vast majority of his real estate holdings, The Real Deal reported in June.

The US allots 10,000 visas annually to prospective immigrants who invest at least $500,000 in areas with low-employment, although lawmakers have heavily criticized the program in recent years following multiple instances of fraud and misuse.