Democrats have launched an investigation into Donald Trump’s chief fundraiser, Meredith O’Rourke, over more than $800 million in corporate donations to the president’s projects, warning that the operation “reeks of potential corruption.”

The inquiry, first reported by The Wall Street Journal, marks an early move by Democrats preparing to wield congressional investigative powers following their victories in last week’s midterm elections.

In a letter sent Wednesday, Senators Elizabeth Warren (D-MA) and Richard Blumenthal (D-CT), alongside Rep. Robert Garcia (D-CA), demanded records detailing O’Rourke’s fundraising activities and her dealings with major corporations, warning her work “reeks of potential corruption.”

The letter, according to The Journal, cites donations from companies including Capital One, SoftBank and Lockheed Martin that it notes subsequently received favorable treatment from the federal government.