Obama has confidence in Secret Service director WASHINGTON (Reuters) - President Barack Obama has confidence in Secret Service director Mark Sullivan and believes he acted swiftly to deal with a scandal in Colombia where agents were alleged to have engaged in misconduct involving prostitutes, the White House said on Tuesday. Eleven Secret Service agents were placed on administrative leave following the incident at a hotel in Cartagena, Colombia, that marred Obama's weekend trip there for a hemispheric summit and raised questions about the agency's culture. "The president has confidence in Director Sullivan," Obama's spokesman Jay Carney told reporters. The director acted swiftly in response to this incident and is overseeing an investigation. Carney said he had not discussed with Obama any concerns that the American public might lose faith in the agency -- whose main duty is protecting the president and his family -- and declined to speculate on any conclusions the probe might reach. He said Obama had not set a timeframe for the investigation and was instead more interested that it be done thoroughly and efficiently. The Secret Service said on Monday it revoked the top security clearance of 11 agents and uniformed division personnel over alleged misbehavior in Colombia. A U.S. official said more than 10 military service members may also have been involved. On Thursday, before Obama arrived, some U.S. agents brought prostitutes back to a beachfront hotel in Cartagena near where the president was due to stay, according to a local police source. The incident came to light after an alleged dispute between an agent and one of the prostitutes. Critics of the Secret Service have suggested the scandal could reflect an erosion of standards and practices among overworked agents that could ultimately leave a president vulnerable to an attack. The president "feels very strongly that the work the Secret Service does, the men and women who protect him and his family...is exemplary, as a rule. They put their lives on the line," Carney said. "There is an investigation on-going that we should let take its course before we speculate about its conclusion," he said. Reporting by Matt Spetalnick; and Jeff Mason; Editing by Sandra Maler and Cynthia Osterman