Washington (CNN) -- A second government report on the Secret Service scandal involving prostitutes in Colombia found no fault with how the agency investigated the matter, according to a copy obtained Friday by CNN.
The report by the Homeland Security Department inspector general's office was scheduled to be released next week.
In its first report last September, the inspector general concluded that the incident in which Secret Service agents brought prostitutes to their Cartagena hotel last spring caused no security threat before President Barack Obama arrived in the country for a summit.
The new report coming out Tuesday said the Secret Service "responded expeditiously and thoroughly" to the incident. The agency immediately pulled 11 agents allegedly involved in the prostitution scandal from the security detail, put them on administrative leave and removed their security clearances.
"Investigative activities included interviewing 232 subjects and witnesses, sending four inspectors to Colombia, reviewing thousands of e-mail messages, and administering 14 polygraph examinations," the report said.
It noted that Obama's security was not compromised and that the agency took subsequent steps intended to prevent similar problems on future trips.
The report made no recommendations, which signaled the watchdog's satisfaction with how the incident was handled.
A third report examining whether the culture of the Secret Service enabled or tolerated such behavior was expected in coming months.
The incident that embarrassed the nearly 150-year-old agency and raised security concerns involved agents who were part of the advance team preparing for Obama's arrival for the Summit of the Americas last April.
They hit the clubs of Cartagena for a night of drinking that ended with bringing women back to their hotel rooms.
A morning-after dispute between one agent and a woman over payment led to exposure of what happened and the ensuing investigations. Nine agents eventually left or lost their jobs.
At a hearing by the Senate Homeland Security Committee in May, Secret Service Director Mark Sullivan insisted the incident was an aberration.
"This is not a cultural issue, this is not a systemic issue," Sullivan said, arguing that similar misconduct hadn't occurred on thousands of other overseas trips by Secret Service agents. "On this particular trip, we had individuals who made very bad decisions."
In addition to the Secret Service agents, 12 military personnel also were cited for their role in the scandal in Cartagena.
Seven U.S. Army soldiers, two Marines and an Air Force member received letters of reprimand, while two members of the Navy refused non-judicial punishment and are awaiting court-martial.
CNN's Ted Barrett and Carol Cratty contributed to this report.