Who Is Rep.-Elect George Santos? His Résumé May Be Largely Fiction.

Kedric Payne, the vice president of the watchdog Campaign Legal Center, and a former deputy chief counsel for the Office of Congressional Ethics, was one of three election law experts consulted by The Times who took issue with the lack of detail.

“This report raises red flags because no clients are reported for a multimillion-dollar client services company,” Mr. Payne said, adding: “The congressman-elect should explain what’s going on.”

The Times attempted to interview Mr. Santos at the address where he is registered to vote and that was associated with a campaign donation he made in October, but a person at that address said on Sunday that she was not familiar with him.

Material omissions or misrepresentations on personal financial disclosures are considered a federal crime under the False Statements Act, which carries a maximum penalty of $250,000 and five years in prison. But the bar for these cases is high, given that the statute requires violations to be “knowing and willful.”

The House of Representatives has several internal mechanisms for investigating ethics violations, issuing civil or administrative penalties when it does. Those bodies tend to act largely in egregious cases, particularly if the behavior took place before the member was inaugurated.

Campaign disclosures show that Mr. Santos lived large as a candidate, buying shirts for his staff from Brooks Brothers and charging the campaign for meals at the restaurant inside Bergdorf Goodman.

Mr. Santos also spent a considerable amount of money traveling — charging his campaign roughly $40,000 in flights to places that included California, Texas and Florida. All told, Mr. Santos spent more than $17,000 in Florida, mostly on restaurants and hotels, including at least one evening at the Breakers, a five-star hotel and resort in Palm Beach, three miles up the road from Mar-a-Lago, Mr. Trump’s private club and residence.

Manuela Andreoni contributed reporting from Rio de Janeiro, Jay Root contributed reporting from Albany, N.Y., and Susan C. Beachy contributed research.