By Victoria McGrane
   Of THE WALL STREET JOURNAL

One of the agents connected with the alleged Secret Service prostitution scandal was staying at the Colombian hotel where President Barack Obama lodged a few days later, a top lawmaker involved in the investigation said Sunday, adding that the development makes the incident "more troubling."

Sen. Joe Lieberman (I., Conn.), chairman of the Senate Homeland Security and Governmental Affairs Committee, said the 12th Secret Service employee implicated in the events was staying at the Hilton in Cartagena, not the Hotel Caribe, the hotel that has garnered most of the public attention. The agent is now on leave.

Mr. Lieberman said the 12th agent's alleged role remained unclear. "But now you're into the hotel where the president of the United States was going to stay." Mr. Lieberman said on CBS's "Face the Nation." "And it just gets more troubling."

In events that unfolded days before the president visited Cartagena for a summit of Western Hemisphere leaders, some of the Secret Service agents are alleged to have brought prostitutes back to their hotel rooms April 11 in an apparent violation of security rules. The incidents came to light after a payment dispute between one of the men and a woman he had brought to his room.

Of the 12 Secret Service employees the agency said were involved in the events, four have resigned, one has retired and the agency is seeking to fire one. Five are on administrative leave, while one was cleared of serious misconduct and will face administrative action, the Secret Service said. In addition, military officials are conducting a separate investigation into 11 service members.

In recent days, the Secret Service employees implicated in the incident have met with investigators to discuss evidence gleaned so far, according to a person familiar with the investigation. The interviews are set to continue Monday.

Mr. Lieberman's committee has opened one of several congressional investigations into the incident. Rep. Peter King (R., N.Y.), who heads the House Homeland Security Committee, is leading another, and on Sunday he released a list of 50 questions he has sent to Secret Service Director Mark Sullivan, seeking a timeline of events.

Mr. King predicted on NBC's "Meet the Press" that "in the next day or so, I think we're going to see more Secret Service agents leaving."

Sen. Susan Collins of Maine, the top Republican on the Senate Homeland Security panel, and Rep. Carolyn Maloney (D., N.Y.), a member of the House Oversight and Government Reform Committee, both said it was possible the incident wouldn't have happened if more women were part of the Secret Service. Women employees comprise 11% of the Secret Service staff, Ms. Maloney said.

A Secret Service spokesman said the 11% figure represents the number of special agents and division officers who are female. When administrative, professional and technical employees are included, the share rises to 25%.

Sen. Charles Grassley (R., Iowa), the top Republican on the Senate Judiciary Committee, has asked the Secret Service for details of the scope of its internal investigation, such as whether it is looking at hotel-room records used by White House advance employees. This group includes military members assigned to the White House agency that coordinate presidential trips.

--Evan Perez and Alan Zibel contributed to this article. Write to -Victoria McGrane at victoria.mcgrane@wsj.com

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