Federal prosecutors are investigating Kushner Companies, the real estate firm owned by the family of Jared Kushner, the president’s son-in-law and senior adviser, over its use of a program that grants visas to wealthy overseas investors.

The authorities, in part, are looking into the role of Mr. Kushner’s sister, Nicole Meyer, according to a person familiar with the matter who confirmed the inquiry.

The investigation centers on the real estate company’s use of the so-called EB-5 program, which offers visas to foreigners in exchange for a $500,000 investment. Critics say the program has weak oversight and lax rules.

At a marketing event in May, Ms. Meyer promoted the company’s connections to the Trump administration as she courted Chinese investors for a pair of luxury apartment towers being built by the Kushner Companies in New Jersey. The project “means a lot to me and my entire family,” she told prospective investors at the Ritz-Carlton Hotel in Beijing.