The lead investigator on the U.S. Department of Homeland Security’s internal review of the Secret Service’s 2012 prostitution scandal resigned over his own incident involving a prostitute last May, the New York Times reported Tuesday night. The investigator, David Nieland, quietly resigned in August after refusing to answer questions from the department’s inspector general about the incident. Nieland has not been charged, current and former department officials reportedly told the newspaper.

Officials told the New York Times that sheriff’s deputies in Broward County, Florida, spotted Nieland entering and exiting a building that was under their surveillance as part of a prostitution investigation in May. When the deputies stopped Nieland after seeing him leave the building, he showed them a badge and said he was part of an undercover human trafficking operation with the Department of Homeland Security. After, Nieland told the inspector general’s office he had been stopped by police due to a broken tailgate light. Officials in the inspector general’s office contacted the Broward County Sheriff’s Office, which revealed Nieland had said he was working on an investigation. After Homeland Security officials said there was no such investigation, sheriff’s deputies interviewed a prostitute who identified Nieland in a photograph and said he had paid her for sex that night. Nieland refused to respond to questions or a subpoena that Homeland Security officials served him. Nieland said the allegation is untrue and declined an interview, the New York Times reported Tuesday.

William O. Hillburg, a spokesperson for the Department of Homeland Security, confirmed Nieland’s resignation with the New York Times and said officials “became aware in early may of this year of an incident in Florida that involved one of our employees.” Hillburg said under law he cannot comment on any specific case. The inspector general’s office and the Broward County Sheriff’s Office are conducting investigations. Nieland has not been charged by federal or local authorities in connection with the incident, according to the New York Times article.

Nieland was previously at the center of a dispute over whether a 2012 investigation into a prostitution scandal in Cartagena, Colombia, involving Secret Service agents was compromised by political and departmental pressures two months ahead of November election. Nieland was asked to lead the investigation of how the Secret Service handled the scandal, in which agents charged with protecting the president during his trip to the port city in April were accused of carousing with prostitutes at a hotel where they were staying prior to the president’s arrival. Almost two dozen Secret Service and U.S. military personnel were handed down some form of punishment after the scandal. Nieland told Senate staffers looking into the matter, “We were directed at the time … to delay the report of the investigation until the 2012 election,” as quoted by the Washington Post. Nieland also indicated that his bosses pressured investigations “to withhold and alter certain information in the report of investigation because it was potentially embarrassing to the administration.”

In 2013, Nieland accused the inspector general’s office of retaliating against him for making those allegations when he was suspended for two weeks without pay after he circulated photographs he had taken of a female intern’s feet. Nieland said he had circulated the photos as a joke. The intern asked to be transferred out of the office following the incident, department officials reportedly told the New York Times.