(CBS News) WASHINGTON - An unfolding investigation shows that 21 Americans representing the U.S. Secret Service and four branches of the military went drinking last Wednesday night and brought prostitutes back to their hotel in Colombia. They were part of a team that was preparing security for President Obama, who attended the Summit of the Americas this past weekend in Cartagena. CBS News chief White House correspondent Norah O'Donnell looks into the developing situation.
Sources tell CBS News that Secret Service agents were offered polygraph tests as part of the investigation. This comes as the scandal has broadened and we've also learned that at least 20 Colombian women were involved in the alleged misconduct.
CBS News has learned that members of the President's security team in Colombia were partying at a Cartagena strip club less than 48 hours before the President's arrival last Friday.
Called the "The Pley Club," it was there that some of those accused first met prostitutes and reportedly paid them $60 to return to the Hotel Caribe. In Colombia, prostitution is legal.
But Republican Sen. Susan Collins, who is on the committee that oversees the Secret Service, has been briefed on the situation. She said she was shocked to learn that between 20 and 21 women were involved.
Collins said investigators uncovered that information by looking back at guest records. "Under the rules of this hotel, guests had to be signed in by the person renting the room. And thus we have the names of the women involved and were able to determine a count," she said.
CBS News has learned that of the 11 Secret Service men involved, two were highly-paid supervisors; three were members of the Counter-Assault Team and three were members of the Counter-Sniper Team.
Ten members of the military are also being investigated:five members of the Army's elite Special Forces; two Navy sailors who were high-ranking enlisted men; two Marines who were low-ranking enlisted men; and one member of the Air Force.
"We know 11 agents and officers and then at least 10 military personnel. Does this suggest that this was part of a culture?" O'Donnell asked Collins.
"It raises questions about the culture," said the senator. "It's also very hard for me to believe that this is the only time that this has ever happened. I am worried that this is the only time that they were caught."
At the White House Tuesday, the president's spokesman would not answer whether he believes there is a larger problem but did say the president stands by Secret Service director Mark Sullivan.
"Why does the president have confidence in the Secret Service director?" O'Donnell asked White House spokesman Jay Carney.
"The president has confidence in director Sullivan. The director acted swiftly in response to this incident and is overseeing an investigation that obviously needs to be conducted."
On Tuesday night, a senior law enforcement official said it is unlikely that there was any security breach by having these women inside the agents' hotel rooms. None of these agents had received their top secret security briefings. It is standard operating procedure that sensitive materials, like the president's schedule, is kept in a locked room guarded by U.S. Marines.