WASHINGTON (Reuters) - U.S. Senate Democrats on Monday pressed Justice Department officials about whether some FBI agents may have leaked damaging information about Democratic presidential candidate Hillary Clinton to Rudy Giuliani, now an adviser to U.S. President Donald Trump, shortly before the 2016 election.

FILE PHOTO: U.S. President Donald Trump's attorney Rudy Giuliani is seen during a visit at the Hadassah Medical Center in Jerusalem, June 7, 2018. REUTERS/Ronen Zvulun

In response to questions from Democrats during a hearing before the Senate Judiciary Committee, FBI Director Chris Wray said his office was “aggressively investigating a number of leaks,” but offered no details.

Monday’s Senate hearing followed publication last week of a report by FBI Inspector General Michael Horowitz that concluded that former FBI Director James Comey made a “serious error of judgment” when he announced he was reopening an investigation into candidate Hillary Clinton’s use of a private e-mail server a few weeks before the election.

Comey became a controversial figure in the 2016 election, drawing accusations from Republicans and Democrats that his handling of an investigation into Clinton’s emails influenced the campaign.

The 500 page Horowitz report also concluded that Comey did not exhibit any political bias in his actions or try to influence the election and did not contest the FBI’s decision not to prosecute Clinton for the email affair.

At Monday’s hearing, Democratic Sen. Patrick Leahy asked Horowitz if his office had investigated “the leaks of FBI personnel who were actively taking steps to sway the election to Mr. Trump” in his report on the FBI’s handling of an investigation into Clinton’s use of email server.

“That’s correct ... We are not able to speak to you about work that might be ongoing,” Horowitz replied.

Sources familiar with the matter confirmed last Friday that Justice Department Inspector General Michael Horowitz’s office was still probing possible leaks to Giuliani or other Trump supporters.

At Monday’s Senate hearing, FBI Director Wray said he was unaware of any ongoing leaks to Giuliani, who now represents the president in Special Counsel Robert Mueller’s Russia investigation.The hearing was the first of two scheduled this week to examine the Horowitz report. Democrats have repeatedly raised questions about leaks to Giuliani because of public comments he made before the election.

Two days before Comey reported to Congress in October 2016 that the FBI was reopening the probe to review the newly discovered Clinton emails, Giuliani appeared on Fox News and predicted some “pretty big surprises” about Clinton.

Horowitz’s report said that a group of retired FBI agents was briefed on the Clinton email investigation on October 21, 2016, days before Comey’s announcement.

The report also discusses widespread problems with leaks to the media and said senior FBI officials were afraid that some officials in the bureau’s New York field office were behind some of the leaks.

Comey has previously said he commissioned an internal probe into the leaks. Trump fired Comey as head of the FBI in May 2017, prompting the appointment of a special counsel now pursuing the Russia probe.