Kevin Trudeau was allowed to remain free until Tuesday, the Chicago Tribune reported. He has organized a fundraising event in Washington for his legal bills.
"It really saddens me, Mr. Trudeau. You're a smart guy. Maybe you're too smart. Perhaps you have outsmarted yourself," U.S. District Judge Robert Gettleman said.
Federal officials say Trudeau has failed to provide an honest accounting of his assets.
Trudeau, an advocate of "natural" treatments, is the author of "The Weight-Loss Cure 'They' Don't Want You to Know About" and other books with similar titles. The Federal Trade Commission alleged he defrauded the public and he has been ordered to pay $37.6 million in fines.
Trudeau, who was convicted of fraud in the 1990s in another case, became a familiar figure on late-night TV infomercials a decade later, pitching remedies for everything from drug abuse to poor reading skills.