FBI agents searched the home of a Los Angeles deputy mayor as part of an investigation into a bomb threat made against City Hall, officials said Wednesday.

The agents searched the home of Brian Williams, who is deputy mayor for public safety, on Tuesday while looking into a bomb threat Williams “allegedly made against City Hall earlier this year,” said Zach Seidl, a spokesperson for Mayor Karen Bass.

In a separate statement, the Los Angeles Police Department identified Williams as the “likely” source of the bomb threat.

“Earlier this year the LAPD responded to a bomb threat made against Los Angeles City Hall,” the department’s statement said. “Our initial investigation revealed that the source of the threat was likely from Brian Williams, Deputy Mayor for Public Safety. Due to the Department’s working relationship with Mr. Williams, the investigation was referred to the FBI. The FBI remains the investigating agency.”

Williams has been placed on administrative leave, said Seidl, who declined to provide additional details.

“The Mayor takes this matter very seriously,” he said. “When the threat was reported, LAPD investigated and determined there was no immediate danger. Following additional investigation, LAPD referred this matter to the FBI for further investigation.”

Williams could not immediately be reached for comment.

FBI spokeswoman Laura Eimiller declined comment, saying the agency cannot confirm or deny any investigation.

Williams has spent nearly two years as a deputy mayor in Bass’ office, working on issues such as police hiring, public safety spending and the search for a new police chief. Before that, he spent seven years as the executive director of Los Angeles County’s Sheriff Civilian Oversight Commission.

Working in Bass’ office, Williams oversaw the police department, the fire department, port police, airport police and the city’s emergency management agency, according to his hiring announcement.