For their part, White House officials took pains to publicly refrain from criticizing the Secret Service.

“The men and women of the Secret Service put their lives on the line every day to protect us; they are heroes, and they have the full confidence of the president of United States,” said Nick Shapiro, a White House spokesman. “The White House asked the United States Secret Service to do a full review, and they are doing that. The United States Secret Service said they made a mistake, and they are taking action to identify exactly what happened, and they will take the appropriate measures pending the results of their investigation.”

Domestic security experts said that the episode raised serious questions about protection for the president. Ronald Kessler, author of “In the President’s Secret Service: Behind the Scenes With Agents in the Line of Fire and the Presidents They Protect,” said threats against the president had increased 400 percent since Mr. Obama took office.

On Friday, agents went to a Virginia winery founded by Mr. Salahi’s father in search of the couple, one administration official said. A phone call to the establishment, Oasis Winery in Hume, Va., was not returned. The winery’s ownership has been the subject of extensive litigation involving disputes within the family. The Salahis and the winery were saddled with hundreds of thousands of dollars of unpaid bills, according to bankruptcy and legal findings in Virginia.

Mr. and Mrs. Salahi, who are known in the area to have a taste for polo and fine wine, are aspiring reality-show celebrities. For months, the couple have been trailed by camera crews with the cable channel Bravo, as it prepared for a new show, “The Real Housewives of D.C.”

Seemingly distancing itself from the Salahis’ actions, Bravo said Friday that it would not comment about “ongoing investigations.” Earlier, the channel said that while its cameras were filming the Salahis before the dinner, producers were told by the couple that they had been invited to it.

The Salahis have not officially been selected for the “Housewives” show.

“The decision as to who will be included in the series will not be made for several months,” Bravo said Friday.