The director of the U.S. Secret Service says he believes last month's scandal in Colombia involving agents and prostitutes does not represent a majority of the agency's nearly 7,000 employees.

Director Mark Sullivan told lawmakers Wednesday that although the alleged behavior of the agents was what he called “reckless,” he believes it was just some individuals doing “some really dumb things.” He added that his agency's investigation did not find that this behavior was a cultural or systemic issue.

Sullivan was appearing before a Senate committee alongside the Acting Inspector General of the Department of Homeland Security Charles Edwards, whose office also is investigating the matter.

Ahead of the hearing, the Washington Post quoted anonymous sources close to the agents in question and familiar with the investigation as saying that at least four of the accused have decided to fight their dismissals, arguing that they were being made scapegoats for behavior the Secret Service has long tolerated.

When asked about the article, Director Sullivan encouraged anyone with additional information to come forward. However, he insisted that any accusation that this type of behavior was condoned or authorized was “absurd.”

Eight of the 13 Secret Service agents accused have lost their jobs after allegedly taking prostitutes back to their hotel rooms in Cartagena, Colombia. The reported misconduct took place just days before U.S. President Barack Obama arrived for the Summit of the Americas.

The agents registered their female companions with the hotel as overnight guests, using their real names and the real names of the women.

Since then, the Secret Service has released new conduct guidelines that specify that agents on international trips may not allow foreigners into their hotel rooms, may not visit so-called “non-reputable” establishments and may not drink alcohol within 10 hours of going on duty.

The new standards also include that agents must abide by U.S. laws while traveling, eliminating the excuse that behavior — such as prostitution, which is legal in Colombia — is acceptable within a certain country.