Public Citizen, a left-leaning watchdog group, on Monday asked the Federal Trade Commission to investigate Trump’s involvement in a multi-level marketing company that he allegedly took money from until four months before declaring his run for the presidency.

The group wants a probe into whether Trump engaged in “deceptive advertising” while shilling for the American Communications Network, a North Carolina-based company that was accused of being a pyramid scheme in an October 2018 lawsuit.

In a letter to FTC chairman Joseph Simons, the group accused Trump of claiming that he was endorsing ACN “not for the money” while receiving “millions of dollars to promote the company.”

“Undertaking an investigation of Mr. Trump would instill confidence in the public that the FTC takes deceptive advertising seriously,” the group wrote.

Trump promoted the company from 2005 to 2015, featuring them on “The Apprentice” and discussing the firm in interviews. Across those appearances, Trump repeatedly stated that he wasn’t taking money to tout the company and referred to ACN execs as “friends of mine.”

“No reasonable viewer, especially after being told that the ACN executives were ‘friends of mine’ would expect that the reason for ACN’s presence on ‘The Apprentice’ was because they paid Mr. Trump,” Public Citizen wrote in the letter.

The demand comes weeks after Trump and his children were hit with a lawsuit in New York accusing them of secretly taking “millions of dollars” from ACN to convince people to sign onto the company. That litigation is reportedly being funded by the Tesseract Research Center, a liberal group.