By Tabassum Zakaria and David Alexander
WASHINGTON, April 16 (Reuters) - The U.S. Secret Service said on Monday it revoked the top security clearance of 11 agents and uniformed division personnel over alleged misbehavior in Colombia, and a U.S. official said more than 10 military service members may also have been involved.
George Ogilvie, a Secret Service spokesman, said of the 11 agency personnel: "Pending investigation, their top secret clearance has been revoked."
The 11 Secret Service agents were placed on administrative leave following alleged misconduct involving prostitutes, in an incident that marred President Barack Obama's weekend trip to Colombia and brought unwelcome attention to the Secret Service.
Before Obama arrived on Thursday, some U.S. agents brought a number of prostitutes back to a beachfront hotel in Cartagena near where the president was due to stay, according to a local police source, setting off the scandal.
Initial reports from Colombian police said five U.S. military service members also were involved in the incident.
But Army Colonel Scott Malcom, a spokesman for U.S. Southern Command, said an interim investigating officer who began working to collect evidence in the case found information indicating more than five may be involved. One U.S. official, who asked not to be named, told Reuters it was "probably more than ten."
Pentagon spokesman George Little declined to say whether the service members involved were members of the Army, Navy, Air Force or Marines. But one Pentagon source said all four services were involved.
Little also declined to describe the nature of the service members' role at the summit Obama was attending, saying only that "they were not associated with presidential security" and "they were performing a support mission to the U.S. Secret Service."
The top U.S. military officer, General Martin Dempsey, said that the service members had let Obama down by distracting from Obama's meeting with Latin leaders in Cartagena, and had embarrassed the Pentagon's top brass.
"LET THE BOSS DOWN"
"We let the boss down because nobody's talking about what went on in Colombia other than this incident," Dempsey, the chairman of the Joint Chiefs of Staff, said at a news conference with Defense Secretary Leon Panetta. "I can speak for myself and my fellow chiefs, we're embarrassed by what occurred in Colombia."
Panetta said General William Fraser, the head of Southern Command, had begun an investigation to determine the facts of the incident.
On Capitol Hill, lawmakers said they were shocked and upset by the allegations, pointing to the security risks involved.
"I am having a call this evening with the director of the Secret Service, because I find this to be so appalling," said Senator Susan Collins, the top Republican on the Senate Homeland Security and Governmental Affairs Committee, which shares jurisdiction over the Secret Service with the Judiciary Committee.
"I can't help but think what if the women involved had been spies, what if they had been members of a drug cartel, what if they had planted equipment or eavesdropping devices?"
Republican Senator Lindsey Graham said that although he did not want to prejudge Sullivan, "it starts at the top, really."
"If the allegations are true, or close to being true, then obviously you've got a leadership problem because things like that don't happen if people are somewhat afraid," he said.
Graham, a former Air Force lawyer, said he believed any members of the military that were involved would be "dealt with severely" if the allegations are true.
The Secret Service agents were sent home, but the military service members stayed through the summit and finished their work while confined to their rooms, officials said.
The only charge against the service members is that they violated curfew. That could mean they were not in their rooms when they should have been, or showed up late or had someone in their room who should not have been there, Malcom said. (Additional reporting by Susan Cornwell. Editing by Warren Strobel and Christopher Wilson)