The US agency announced on Tuesday that two more employees have resigned and a third is having his national security clearance revoked, the Associated Press reported.
Representative Peter T. King, the chairman of the House Committee on Homeland Security, said one of the resigning agents stayed at the Hilton hotel in the Caribbean city of Cartagena, around 1,000 kilometers (620 miles) north of the Colombian capital, Bogota, where Obama stayed for the sixth Summit of the Organization of American States (OAS). The others stayed at the nearby Hotel Caribe.
Of the 12 Secret Service agents originally implicated in the Colombia misconduct scandal, a total of three employees have retained their posts, six have resigned, two have been dismissed, and one has retired.
"The Secret Service is committed to conducting a full, thorough and fair investigation in this matter, and will not hesitate to take appropriate action should any additional information come to light," Secret Service Assistant Director Paul Morrissey said in a statement.
There are reports that the US Secret Service and military personnel took as many as 21 female escorts back to their hotel rooms on the night of April 11, just before Obama’s arrival in the coastal city to attend the Americas summit.
The scandal erupted after a fight over payment between one of the Colombian escorts, and a Secret Service employee spilled into the hallway of the Hotel Caribe the following morning, leading to the involvement of the local police.
Obama acknowledged Tuesday that the scandal was "a little distracting" and pressed for perspective.
"These guys are incredible. They protect me. They protect Michelle. They protect the girls. They protect our officials all around the world," the US president said.
"A couple of knuckleheads shouldn't detract from what they do," Obama added. "What these guys were thinking, I don't know. That's why they're not there anymore."
The Colombia sex scandal caused an embarrassment for the US administration and overshadowed Obama's participation at the OAS summit.