Real estate empire the Kushner Companies has been served with a grand jury subpoena relating to paperwork practices dating to the period when White House Senior Advisor and presidential son-in-law Jared Kushner served as CEO.

An Associated Press (AP) investigation last month revealed that the Kushner Companies repeatedly filed forms with the New York City Department of Buildings claiming they owned no rent-controlled units while actually possessing hundreds of such units in Queens, New York apartment buildings they purchased in 2015.

Those filings reportedly allowed the Kushner Companies to raise rents and, in turn, sell those buildings at a great profit two years later, at which point Jared was no longer at the company’s helm, but serving in the Trump administration alongside his wife, Ivanka Trump.

On Thursday, a grand jury serving under the auspices of federal prosecutors from the Brooklyn-based U.S. Attorney’s Office for the Eastern District of New York approved subpoenas based on that AP report, demanding documentation as to how the allegedly false forms were prepared and by whom.

The subpoena was first reported in the Wall Street Journal Friday. “Kushner Companies has nothing to hide and is cooperating fully with all legitimate requests for information, including this subpoena,” a Kushner spokeswoman told the Journal.

“We believe that this subpoena, which has already been complied with, was issued based solely on an article that appeared in the press the day before it was issued,” the spokeswoman continued in reference to the AP investigation.

In response to the original AP reporting, the Kushner Companies denied all wrongdoing. “[I]f mistakes or violations are identified, corrective action is taken immediately,” they said in a statement, claiming the allegedly false filings were prepared by a third party.

“Kushner would never deny any tenant their due-process rights,” the statement continued, claiming Kushner Companies “has renovated thousands of apartments and developments with minimal complaints over the past 30 years.”

The explanation was not enough to stave off a New York City Council investigation, and now that scrutiny evidently has expanded to a federal investigation, although as is typical in grand jury inquiries, the U.S. Attorney’s Office for the EDNY could neither confirm nor deny its existence.

This Kushner Companies was founded by Jared’s father and predecessor as head of the Kushner Companies, Charles Kushner, who was convicted on 18 felony counts in 2005, and since Jared’s departure has been led by Jared Kushner’s sister Nicole Kushner Meyer. The company has repeatedly found itself under federal pressure over the last year, most notably in connection with their improper promotion of the controversial EB-5 visa program – complete with hints at Jared’s influence in the administration – to entice Chinese investors to put large sums into a Kushner building project in New Jersey with promises of American residency.

One of the Kushner Companies main financiers, Deutche Bank, also faced subpoenas last year, reportedly aimed at banking activity related to the Kushners and their real estate business.