A group of lawmakers demanded answers from the White House this week following a ProPublica investigation revealing that a top aide to the president intervened to secure a $620 million Pentagon loan to a startup linked to the president’s eldest son.

ProPublica’s reporting “reveals a staggering level of corruption and influence peddling that superseded this process, enriching the President’s son at the expense of U.S. national security and taxpayer dollars,” wrote the group of Democratic lawmakers, including Sens. Elizabeth Warren of Massachusetts, Richard Blumenthal of Connecticut and Mazie Hirono of Hawaii as well as Reps. Jason Crow of Colorado and Mike Levin of California.

Last year, the Pentagon announced the loan to Vulcan Elements, a small North Carolina startup, about three months after Donald Trump Jr.’s venture capital firm took a stake of undisclosed size in the rare-earth magnet company.

Interviews and Defense Department records reviewed by ProPublica show that the request to lend to the firm was made by Peter Navarro, who serves as the president’s senior counselor for trade and manufacturing and is a friend of Trump Jr.’s.

Of the dozens of companies the Pentagon was considering funding at the time, Vulcan’s was the only deal initiated by a top aide to the president, an official at the Pentagon who was not authorized to speak publicly told ProPublica.