Secret Service Director Mark Sullivan says an agent was fired in 2008 after being caught in a Washington prostitution scandal.

Sullivan told a Senate panel that the on-duty agent was caught trying to hire an undercover police officer and was "separated from the agency" a month later.

Sullivan is testifying before the Senate Homeland Security and Governmental Affairs Committee about the Colombia prostitution scandal that erupted after an officer and a Colombia prostitute argued over payment at a Cartagena hotel last month.

In his first public statements about the scandal, Sullivan apologized for the employees' behavior.