As the Secret Service investigates what may be the worst scandal in the organization’s history, the answer to one looming question could be even more explosive for the agency: were any of the women in the Colombian prostitution incident underage?

If it turns out anyone was under 18, there could be criminal charges for the U.S. agents and military personnel involved.

Darrell Issa, the Republican chairman of the House Government Oversight and Reform Committee, told reporters Thursday that neither he nor the director of the Secret Service, Mark Sullivan, knows the answer to that question.

“In the case of the 11 agents, the primary determination is you can’t determine to charge or not charge somebody until you know whether a crime is committed,” Issa said. “Under U.S. law, if any of these women are under 18—I can tell you we do not know and Director Sullivan does not have actual contact/picture matched up to verify that as far as I know. When he does, I would expect a call, because that would be a relief to many of us to not have on top of everything else.”

Issa cited two laws that make it a crime to have sex with minors abroad. “U.S. laws passed in 2003 and 2006 were designed to prevent sex vacations causing harm to underage women,” Issa said. “We have to respect some things, but going internationally anywhere to have sex acts underage is prohibited under U.S. law.”

A spokesman for the Secret Service declined to discuss the investigation.

Thus far, the scandal surrounding President Obama’s visit to Colombia has led to three agents, at least one of whom is a supervisor, losing their jobs.

Both Issa and Rep. Elijah Cummings, the ranking Democrat on the oversight panel, said they would wait for the Secret Service to finish its investigation before launching their own probe. For now, the lawmakers said they were conducting an “over-the-shoulder investigation,” but are prepared to act if they are not satisfied with the Secret Service’s efforts. Both also said they want confirmation of the nationalities of the women involved.

On Thursday, the New York Daily News published four photographs of a woman whom the paper said is the escort who triggered the investigation—a 24-year-old who neighbors say is the single mother of a 9-year-old.

Cummings and Issa wrote to Sullivan on Wednesday, asking a series of questions about the investigation, including whether all of the women involved were older than 18 years of age.

Cummings also said the committee wants to know if there is a culture at the Secret Service where engagement with sex workers is tolerated. “I think that’s part of what our questions are going to, because we asked about any history of these kinds of things happening,” Cummings said. “In talking to Sullivan, I asked him that question and he said he did not know of any kind of culture like this.”

Sullivan, he added, said “he’d never seen anything like it, but I can tell you he was extremely upset, embarrassed, and made it clear that he was going to get to the bottom of it immediately.”