April 18, 2012— -- Secret Service agents are being forced out of their positions as officials investigate the alleged hiring of prostitutes and other questionable behavior during a presidential visit to Colombia.
"Although the Secret Service's investigation into allegations of misconduct by its employees in Cartagena, Colombia, is in its early stages, and is still ongoing, three of the individuals involved will separate or are in the process of separating from the agency," said Paul S. Morrissey, the assistant director of the U.S. Secret Service Office of Government and Public Affairs, in a written statement.
One supervisory employee was allowed to retire and another was "proposed for removal for cause," the statement said. In addition, a non-supervisory employee resigned.
The employee proposed for removal has been given notice and will be allowed to fight the move, the Secret Service said.
Eight other Secret Service employees remain on administrative leave with suspended security clearances.
In addition, some Secret Service personnel are now under investigation for possible drug use in Colombia, ABC News confirmed.
U.S. inspectors are now on the ground in Colombia canvassing night clubs, interviewing hotel employees and collecting hotel surveillance video. Many of the suspected prostitutes have been identified and will be interviewed, officials told ABC News.
Prostitution is legal in Colombia, but officials are concerned about the use of prostitutes by U.S. personnel for ethical and security reasons.
"Since these allegations were first reported, the Secret Service has actively pursued this investigation, and has acted to ensure that appropriate disciplinary action is effected," Morrissey said. "We demand that all of our employees adhere to the highest professional and ethical standards and are committed to a full review of this matter."
The Secret Service is expected to conduct polygraph examinations with the agents involved in the scandal, which also allegedly involves 10 members of the U.S. military who were working on the trip to Colombia in a support role.
The news of the employee removals comes as Congressional committees are lining up to review the Secret Service's actions and culture that led to the scandal.
On Wednesday, the chairman and ranking Democrat on the House Committee on Oversight and Government Reform, Rep. Darrell Issa, R-Calif., and Rep. Elijah Cummings, D-Md., wrote to Mark J. Sullivan, the director of the U.S. Secret Service, about potential security concerns.
"The facts as you described them raised questions about the agency's culture," Issa and Cummings wrote. "The incident in Cartagena is troubling because Secret Service agents and officers made a range of bad decisions, from drinking too much, to engaging with prostitutes, to bringing foreign nationals into contact with sensitive security information, to exposing themselves to blackmail and other forms of potential compromise."
Next week, Homeland Security Secretary Janet Napolitano is expected to appear before the Senate Judiciary Committee in a previously planned oversight hearing. Today, in a statement provided to ABC News, she voiced her support for Secret Service Director Sullivan.