Three Secret Service personnel tied to Colombia prostitution scandal to leave agency

The Secret Service announced late Wednesday that three of its personnel connected to the Colombia prostitute scandal--two supervisors and one agent--will leave the agency while eight more remain under investigation.

The agency is carrying out a full probe into the incident, including lie detector tests and witness interviews in Colombia, the assistant director of the U.S. Secret Service Office of Government and Public Affairs, Paul Morrissey, said in a statement.

"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 Morrissey, whose office is running the probe.

One supervisor was allowed to retire from the agency. Another "has been proposed for removal for cause," triggering a process in which that person can hire a lawyer and challenge the case against him. And one agent has resigned.

"The remaining eight employees continue to be on administrative leave. Their security clearances remain suspended," Morrissey said.

"The Secret Service continues to conduct a full, thorough and fair investigation, utilizing all investigative techniques available to our agency. This includes polygraph examinations, interviews with the employees involved, and witness interviews, to include interviews being conducted by our Office of Professional Responsibility in Cartagena, Colombia," he said.

[Related: Escort says Secret Service agent offered her just $30 for sex]

"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. 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," Morrissey said.

Meanwhile, ABC News' Jake Tapper obtained a letter from the Republican chairman and Democratic ranking member of the House Oversight and Government Reform Committee to Secret Service director Mark Sullivan warning that the agents, who allegedly brought prostitutes to their rooms at the Hotel Caribe, may have brought the escorts "into contact with sensitive security information." Congressmen Darrell Issa and Elijah Cummings also requested a range of details from the agency, including a determination as to whether the women involved were all over 18 years of age.

In their letter, Issa and Cummings bluntly told Sullivan that "your task is to restore the world's confidence in the U.S. Secret Service."

"Our nation's capacity to protect the President, the Vice President, and visiting foreign leaders, among others, is dependent on the character and judgment of the agents and officers of the U.S. Secret Service. The actions of at least 11 agents and officers in Colombia last week showed an alarming lack of both," the lawmakers wrote in the letter obtained by ABC.