Secret ServiceThe Secret Service may have been misbehaving. ¬†Allegations arose last night of misconduct by members of the protective group, threatening cast a dark cloud over President Obama’s trip to Colombia for a regional summit.

Last night, a caller told the Associated Press that the misconduct involved prostitutes in Cartagena, site of the Summit of the Americas this weekend.

The White House would not comment on the matter, but did not dispute those allegations.

An anonymous U.S. official said that 12 agents were involved.

The alleged indiscretions occurred prior to Obama’s arrival Friday in the Colombian port city for meetings with 33 other regional leaders. Secret Service spokesman Ed Donovan said the agents in question were sent home and replaced with other agency personnel.

“These personnel changes will not affect the comprehensive security plan that has been prepared in advance of the president’s trip,” Donovan said.

Still, the misconduct rumors were a black eye the president and his entourage while guests of the Colombian government.

Obama was to hold two days of summit meetings before returning to Washington D.C. on Sunday night.

The agents at the core of the allegations had stayed at Cartagena’s Hotel Caribe.

An anonymous hotel employee said the agents arrived at the hotel about a week ago. The employee said the Secret Service agents drank heavily during their stay.

The agents reportedly left on Thursday, a day before Obama arrived for the weekend summit.

Jon Adler, president of the Federal Law Enforcement Officers Association, said the accusations related to at least one agent having involvement with prostitutes in Cartagena. The association represents federal law enforcement officers, including the Secret Service.

The matter has now been turned over the agency’s Office of Professional Responsibility, which handles the agency’s internal affairs.