WASHINGTON — A congressman says Hillary Clinton’s former chief of staff, Cheryl Mills, and two other staff members were granted immunity deals in exchange for their cooperation in the now-closed FBI investigation into Clinton’s use of a private email server as secretary of state.

Utah Rep. Jason Chaffetz, chairman of the House Oversight and Government Reform Committee, tells the Associated Press that Mills gave federal investigators access to her laptop on the condition that findings couldn’t be used against her. Chaffetz says, “No wonder they couldn’t prosecute a case. They were handing out immunity deals like candy.”

In a statement to CBS News, the Utah congressman said he has “lost confidence in this investigation.”

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“I question the genuine effort in which it was carried out.” Chaffetz said. “Immunity deals should not be a requirement for cooperating with the FBI.”

Chaffetz says 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 were previously identified as receiving immunity deals.