"The information available to the Committee at this time raises serious questions about how the FBI applied the rule of law in its investigation of classified information on Secretary [Hillary] Clinton’s private email server," said the report released by Senator Ron Johnson, along with Republicans on the Senate's Homeland Security and Governmental Affairs Committee.
The senators also pointed to other details uncovered in the investigation, including an exchange of text messages between two FBI employees involved in a personal relationship discussing the need for an "insurance policy" to mitigate the "risk" of then-candidate Donald Trump becoming president.
"Taken together, this information warrants further inquiry," the report said.
Clinton used a private server and email accounts for official business during her tenure as secretary of state from 2009 to 2013. The FBI closed the investigation in July 2016, and concluded that while Clinton was "extremely careless," it would not recommend filing any charges.