Another dozen military personnel also have been implicated. Defense Secretary Leon Panetta said this week that all have had their security clearances suspended.
The Defense Department briefed senators on Wednesday about its investigation, but Sen. John McCain, R-Ariz., said Thursday he was unsatisfied with what the Pentagon told lawmakers. Unlike for civilian U.S. government employees, soliciting prostitutes is a criminal offense for U.S. military personnel even in countries where prostitution is otherwise legal.
"Secretary Napolitano and especially the director of the Secret Service has been pretty forthcoming in many aspects of this, unlike the Pentagon, which has completely stonewalled, using the excuse that a Uniform Code of Military Justice — as you know, that's the military law — somehow is a barrier to us receiving information," McCain said the CBS program "This Morning."
Graham proposed Thursday that military commanders and Secret Service supervisors should conduct surprise visits for personnel working overseas.
"People get away from home, get deployed and believe they're on vacation," he said. "They work hard, but they believe their off-duty time is something that doesn't matter. It does matter."
Associated Press writers Larry Margasak, Jim Kuhnhenn and Ben Feller contributed to this report.
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