The Secret Service said Thursday it was investigating the report.
"The recent investigation in Cartagena has generated several news stories that contain allegations by mostly unnamed sources. Any information that is brought to our attention that can be assessed as credible will be followed up on in an appropriate manner," said Secret Service spokesman Max Milien in a statement.
The Department of Defense did not respond to a request for comment.
On Sunday, House Oversight Committee Chairman Darrell Issa (R-Calif.) said he believed that there were instances of misconduct by Secret Service agents prior to the Colombian prostitution scandal that has led to a number of resignations and firings and shaken confidence in the agency tasked with protecting the president.
"Things like this don't happen once if they didn't happen before," Issa told CBS News.
Sen. Chuck GrassleyChuck GrassleySessions can put the brakes on criminal justice 'reform' GOP senator: Trump budget chief could face confirmation 'problems' Jeff Sessions will protect life MORE (R-Iowa), the ranking member of the Senate Judiciary Committee, said the report was further evidence of the need for an independent investigation into the agency.
“This latest allegation only reaffirms the need for independent investigations by the Inspector General. Regardless of whether the incidents were previously referred to internal investigators, they need to be examined," Grassley said. "There are rumors flying about various incidents over several years about the conduct of Secret Service personnel, as well as other law enforcement and military personnel in locations around the world. The only way to put to rest the rumors of a much wider problem is for the allegations to receive transparent and independent reviews.”
But Wednesday, Napolitano insisted that there was no evidence of additional misconduct.
“There was nothing in the record to suggest that this behavior would happen and it really was, I think, a huge disappointment to the men and women of the Secret Service,” Napolitano said.