Hillary Clinton’s former chief of staff Cheryl Mills and two other staffers were granted immunity as part of the now-closed FBI probe into the former secretary of state’s email practices, according to a top House Republican who questioned whether the numerous deals hindered the bureau’s ability to build a case.

"This is beyond explanation,” House oversight committee Chairman Jason Chaffetz, R-Utah, said in a statement Friday. “The FBI was handing out immunity agreements like candy. I've lost confidence in this investigation and I question the genuine effort in which it was carried out.”

The arrangements detailed by Chaffetz bring the total number of publicly known immunity deals in the Clinton case to five.

Chaffetz first revealed the additional deals in an interview with The Associated Press, saying “no wonder they couldn't prosecute a case.” He said Mills gave federal investigators access to her laptop on the condition that findings couldn't be used against her.

“Immunity deals should not be a requirement for cooperating with the FBI,” Chaffetz said in his statement.

Chaffetz said the two others granted immunity were John Bentel, then-director of the State Department's Office of Information Resources Management, and Clinton aide Heather Samuelson.

Two other people including former IT specialist Bryan Pagliano were previously identified as receiving immunity deals as well. Chaffetz’ committee voted Thursday to recommend holding Pagliano in contempt of Congress after he again ignored a subpoena to appear before the oversight panel.

Democrats on the oversight committee pushed back at Chaffetz’ claims Friday, saying the immunity agreements were very limited and did not extend to statements to the FBI or assertions to other investigators, or testimony before Congress.

“It’s beyond disappointing—but not surprising in light of the election—that Republicans are rushing to leak inaccurate information about this very limited agreement between Ms. Mills and the Justice Department,” Rep. Elijah Cummings, D-Md., top Democrat on the oversight committee, said in a statement. “Ms. Mills was not immunized for any statements she made to the FBI, Congress, or other investigators. Of course, Republicans are trying to make political hay out of this, but the facts are that Ms. Mills cooperated fully with the Justice Department and Congress.”

Clinton campaign spokesman Brian Fallon said Republicans are “trying to make something out of nothing by rummaging through the files of a Justice Department investigation that was closed months ago without any charges whatsoever.”

But Chaffetz’ revelations fueled GOP concerns about the nature of the FBI investigation, which determined Clinton’s actions were extremely careless but did not lead to any criminal prosecution.

Donald Trump spokesman Jason Miller said the multiple immunity deals "shows this was without a doubt a criminal scheme.”

The yearlong investigation by the FBI focused on whether Clinton sent or received classified information using the private server, which was not authorized for such messages.

FBI Director James Comey said in July that his agents hadn't found evidence to support any criminal charge or direct evidence that Clinton's private server had been hacked. He suggested that hackers working for a foreign government may have been so sophisticated they wouldn't have left behind any evidence of a break-in.

Chaffetz said he is looking forward to asking Comey questions about the immunity deals when Comey testifies Wednesday before the House Judiciary Committee.

Fox News' Chad Pergram and Catherine Herridge and The Associated Press contributed to this report.