The Justice Department's inspector general notified the ranking members of the Senate Homeland Security Committee of the findings in December, CNN reported. The report became public this week after Sen. Susan Collins, R-Maine, asked Michele Leonhart, head of the Drug Enforcement Administration, what action the agency is taking.
The inspector general said three DEA agents were involved and all have admitted using Colombian prostitutes themselves. One set up a date for the Secret Service agent, one said he was too drunk that night to remember what had happened and a third was at dinner with the others but not involved in the prostitute arrangement.
The DEA said the Board of Professional Conduct is reviewing the agents' actions.
Twelve Secret Service agents were in Cartagena last April in advance of President Obama's visit for a summit meeting. Nine have quit or retired while three were found not to have engaged in misconduct.