Three more US Secret Service agents have quit over a widening sex scandal in Colombia, as President Barack Obama got his first briefing on the incident from the agency's director.
The new resignations bring to six the number of agents who have lost their jobs over claims that they brought prostitutes back to their hotel in the Caribbean resort of Cartagena, host of last weekend's Summit of the Americas.
A 12th member of the elite protection agency has now been implicated in the incident.
The Secret Service said in a statement announcing the resignations that one employee had been cleared of misconduct, but would face administrative action.
"The Secret Service continues to conduct a full, thorough and fair investigation, utilizing all investigative techniques available to our agency," the statement said.
Including military officers, who were also in Cartagena to protect the president, there are now 23 Americans under investigation over the late night spree of drinking and alleged inappropriate behaviour.
The agency is using polygraph lie detector techniques in the probe.
Mr Obama has said he will be "angry" if details of the scandal aired in the press are true.
The Cartagena incident first came to light after a dispute over payment involving one of the women led police to be called to the hotel and unleashed the biggest scandal in the presidential bodyguard's nearly 140-year history.
The New York Times on Wednesday published comments from the 24-year-old single mother at the centre of the incident, saying a Secret Service agent had reneged on a deal to pay her $800 for the night and ended up paying only $30.
