The White House counsel initiated the inquiry out of what Carney called "due diligence" in the wake of evidence of misconduct by members of the Secret Service and military who were in Cartegena ahead of President Obama's arrival.
"There have been no specific, credible allegations of misconduct by anyone on the White House advance team or the White House staff," Carney told reporters, adding the review was completed during the weekend and "came to the conclusion that there's no indication that any member of the White House advance team engaged in any improper conduct or behavior."
Carney declined to go into details of the inquiry.
The comment came as the Department of Homeland Security said it would look into the scandal following revelations a Secret Service agent tied to the prostitution scandal stayed at the hotel where Obama stayed.
"It is not clear what the agent's alleged role in the scandal was -- or what he "is being charged with and why he's been put on administrative leave -- but now you're into the hotel where the president of the United States was going to stay," Senate Homeland Security and Governmental Affairs Committee Chairman Joseph Lieberman, Ind-Conn., said on CBS' "Face the Nation" Sunday.
"And it -- it just gets more troubling," he said.
The agent implicated in the events was staying at the Hilton in Cartagena, not the Hotel Caribe, the hotel that has received most of the public attention.
"The White House advance person knows exactly where the president is going to be at any time," Lieberman said separately on "Fox News Sunday." "If anybody -- thinking the worst -- wanted to attack the president of the United States, one of the ways they might find out -- the path he would follow in Cartagena -- is by compromising the White House advanced personnel."
The Secret Service and the Pentagon are conducting parallel investigations of events, including interviews with women believed to be prostitutes brought into Hotel Caribe April 11, two days before Obama arrived for the weekend Summit of the Americas.
The incident, which continued into the morning of April 12, came to light after a payment dispute between one of the men and a woman he had brought to his room, lawmakers have said.
As many as 21 women were involved, the lawmakers say.
Of the 12 Secret Service employees the agency said were involved, four have resigned, one has retired and the agency is seeking to fire one.
Five are on administrative leave, while one was cleared of serious misconduct and will face administrative action, the Secret Service said.
At least four congressional committees are receiving daily briefings on the investigation from Secret Service officials, the committee heads say. The House Oversight and Government Reform Committee and the House Homeland Security Committee have made formal requests for full information on the scandal by as early as Friday.
House Homeland Security Committee Chairman Peter King, R-N.Y., said on NBC's "Meet the Press" Sunday he had "full confidence" in Secret Service Director Mark Sullivan.
"From every indication I've seen, from the moment this scandal broke until now, there's no attempt to cover anything over," King said. "Every possible lead is being examined."