Four probes set in Secret Service prostitution scandal President Barack Obama speaks in Washington April 11, 2012. WASHINGTON, April 16 (UPI) -- President Barack Obama said he would be angry if an alleged prostitution scandal involving U.S. Secret Service agents proved true, as four investigations began. "If it turns out that some of the allegations that have been made in the press are confirmed, then of course I'll be angry, because my attitude with respect to the Secret Service personnel is no different than what I expect out of my delegation that's sitting here," Obama said in Cartagena, Colombia, at the end of the Summit of the Americas before flying to Washington. "We're representing the people of the United States," he said, "and when we travel to another country, I expect us to observe the highest standards because we're not just representing ourselves, we're here on behalf of our people. And that means that we conduct ourselves with the utmost dignity and probity. And obviously what's been reported doesn't match up with those standards," he said. Two congressional committees, the Secret Service itself and the U.S. Defense Department began or said they would begin investigations into allegations 11 agents and officers, including two supervisors, brought prostitutes to their hotel rooms in Cartagena last week while preparing for Obama's visit. The U.S. military said over the weekend five military personnel may have been involved as well. The Secret Service put the agents and officers on administrative leave and immediately replaced them with other service members, the agency said. House Oversight and Government Reform Committee Chairman Darrell Issa, R-Calif., told CBS's "Face the Nation" Sunday his committee's investigation wouldn't focus on the agents but on the agency as a whole. "The question is, is the whole organization in need of some soul searching, some changes, before the president, the vice president, members of the Cabinet are in danger?" he said. Issa, who became a millionaire making automobile security devices, said the Secret Service employees could have made themselves susceptible to blackmail, and said the number of agents involved might have been 20, not just the 11 put on administrative leave. He didn't elaborate on the blackmail allegation or how he came to the higher number of agents allegedly involved. "Things like this don't happen once if they didn't happen before," he said. House Homeland Security Committee Chairman Peter King, R-N.Y., whose committee oversees the Secret Service, told The Wall Street Journal his committee, like Issa's, would look at underlying issues. "How do you take action to make sure it does not happen again and conduct is not being tolerated?" he said. King expressed faith in Secret Service Director Mark Sullivan, who is overseeing an internal investigation. The Defense Department said it would begin its own inquiry into the five military personnel working with the Secret Service and staying in the same hotel who allegedly violated a curfew and may have participated in the alleged misconduct. Officials emphasized Obama was never in any danger because of the episode. The agents, who haven't been identified, were caught after a Cartagena prostitute refused to leave a Secret Service agent's hotel room until she was paid, King told the Journal. She stayed in the room past 7 a.m., in violation of hotel policy, prompting the hotel manager to go to the room, King said, explaining he was briefed on the details by the Secret Service. When the agent wouldn't open the door, the manager called police, after which the agent let them in. The woman said she wouldn't leave until she was paid the money she was owed by the agent. The agent denied owing her money but paid anyway, King said. The woman left and the situation was resolved without arrests. Cartagena police filed a report to the U.S. Embassy because the situation involved a foreign national, King said. The embassy began an investigation. Despite the scandal, Obama said he still had the highest confidence in the Secret Service. "These men and women perform extraordinary service on a day-to-day basis protecting me, my family, U.S. officials," he said in Cartagena. They do very hard work under very stressful circumstances, and almost invariably do an outstanding job. And so I'm very grateful to the work that they do.