(CNN) -- Misconduct with prostitutes by U.S. Secret Service agents handling travel security for the president in April was not a one-off episode, according to a media report citing an investigation by the Department of Homeland Security.
Sen. Joseph Lieberman, chairman of the Homeland Security and Governmental Affairs Committee, issued a statement Friday complaining about unfair "selective leaks" and said he will wait for the final report "before making any judgments."
The Homeland Security inspector general's results "contradict" previous testimony before Congress by Secret Service Director Mark Sullivan about the incident during President Obama's trip to Colombia to attend the Summit of the Americas, ABC News reported Thursday.
But a Secret Service official with knowledge of the investigation told CNN on Thursday that Sullivan's statements in a hearing in May had been "truthful."
CNN has not seen the investigation results and cannot confirm the reported allegations.
"The investigation is continuing," said Bill Hillburg, a spokesman for the inspector general. "We never make comments on ongoing investigations."
A Department of Homeland Security official said it is not unusual for Congress to be given updates on an investigation while it's in progress. But the official could not provide details on what information might have been shared and with how many people on Capitol Hill.
The DHS inspector general was tasked with looking at three things. The first centered on what happened when Secret Service agents partied with prostitutes in Cartagena in April. The inspector general said there was misconduct but presidential security was not compromised.
Investigators are still looking at how the Secret Service handled its own investigation of what happened and at whether there are cultural problems within the Secret Service that led to the misconduct.
As part of the advance detail before Obama's arrival to attend the summit, a dozen agents hit the clubs of Cartagena for a night of drinking that ended with them bringing women back to their hotel rooms.
Some of the women received money, and others did not ask for any, but in one case, an agent refused to pay, and the woman summoned a police officer.
Prostitution is legal in certain areas of Colombia, but the news that some Secret Service agents were drinking heavily and taking prostitutes to their hotel rooms raised security concerns and tarnished the reputation of the agency charged with protecting the president.
Testifying before Congress in May, Sullivan insisted the incident was an aberration -- just poor choices by a dozen agents under the influence of alcohol.
"This is not a cultural issue, this is not a systemic issue," he told the Senate Homeland Security Committee back then, saying that similar misconduct hasn't occurred on thousands of other overseas trips by Secret Service agents.
However, the DHS inspector general's investigation reportedly reveals that Secret Service agents associated with prostitutes on previous trips to El Salvador, Panama, Romania and China.
"It is very difficult to respond to specific inquiries from a draft report that we haven't had an opportunity to review," a Secret Service official said in response to the media report Thursday.
"Director Sullivan's testimony, approximately one month after the Cartagena incident, was truthful based on the Secret Service's investigative findings to date," said the official, who is not authorized to speak to the media and wished not to be named.
Agents had not confessed to prior dealings with prostitutes when Sullivan was briefed before testifying, the official said. "One agent, who later admitted to the DHS Office of the Inspector General that he had indeed engaged in prior misconduct" had previously denied doing so to the Secret Service.
Questions have also been raised about Sullivan's response when asked whether any of the prostitutes had connections to criminal or terrorist activity. Sullivan replied that checks indicated the women had no such ties. But at the time, the Secret Service had some information indicating the name of at least one of the women might have been in a criminal database.
"The Secret Service did receive information that there potentially was a partial match to the name of one of the women, but at the time Director Sullivan was briefed that it was not a match," said the Secret Service official with knowledge of the investigation. The official went on to say the Secret Service was "never able to confirm a connection."
The inconsistency between the new investigation and Sullivan's past accounts has prompted a new call for answers from the Obama administration by lawmakers on Capitol Hill.
Republican Sen. Ron Johnson of Wisconsin, the ranking member of the Senate oversight subcommittee, released letters concerning the investigation late Thursday that he had sent in early October to Sullivan but also to Homeland Security Secretary Janet Napolitano, White House Chief of Staff Jacob Lew and Attorney General Eric Holder.
Johnson said he has received no response to his inquiries.
In his letter to Sullivan, Johnson expresses suspicions that the Secret Service director's testimony and other assurances concerning agents' conduct may have been misleading.
He said his office's reviews of the inspector general's report ... lead me to believe that these assurances were false."
CNN's Carol Cratty and Tom Cohen contributed to this report.