Secret Service Director Mark Sullivan. (Haraz N. Ghanbari/AP)

Secret Service Director Mark Sullivan is facing questions about whether he gave misleading information to Congress about security risks posed by a prostitution scandal that involved agents in Cartagena, Colombia, according to three government sources familiar with an internal investigation.

Sullivan told members of Congress that agents who partied with prostitutes on the April trip to Cartagena had not compromised President Obama’s security, and he stressed that the agency found the women had “no connection” to criminal or counterintelligence activities.

But at the time of the May hearing, intelligence officers had told Sullivan’s office they were still looking into some evidence that suggested at least one of the women could be listed in a database of known criminals, according to two government sources.

The officers later found the woman had a name similar to a listed criminal but was not the same person.

The Department of Homeland Security’s Office of Inspector General turned up the conflict while examining how Sullivan and his office investigated the agents. The news that Sullivan’s testimony had been questioned by the inspector general’s office was first reported by Fox News on Tuesday evening.

A senior Secret Service official said Wednesday that Sullivan did not knowingly mislead Congress and was truthfully answering a question from Sen. Susan Collins (R-Maine) about whether any of the prostitutes were known criminals or spies.

“Director Mark Sullivan and the Secret Service have conducted a fair and thorough investigation,” Secret Service spokesman Ed Donovan said in a statement. “The agency response to those with oversight responsibility has been timely and truthful. We will continue to respond to the DHS-OIG and Congressional inquiries in that manner.”

Collins, the ranking member of the Senate’s Committee on Homeland Security and Governmental Affairs, said in a statement that she will reserve judgment on Sullivan’s testimony “until all the facts are known.”

Joshua Hochberg, Sullivan’s attorney, did not return calls seeking comment.

The inspector general’s investigation is the second to focus on the Cartagena scandal, one of the agency’s most serious embarrassments.

The first, completed last month, focused on the details of agents’ socializing and drunken partying on April 12, one day before Obama arrived in Colombia.

Inspector General Charles K. Edwards told Congress that his office found 13 male Secret Service employees had personal encounters with foreign women, and that six of the women were paid for sex.

Edwards’s office is expected to finish its second report sometime after Thanksgiving. The probe has found evidence the agency pushed some agents who had been implicated to quickly resign and denied them due process, sources close to the agents have told The Washington Post, a charge agency officials have denied.