The State Department's inspector general has already conducted an investigation that found serious lapses in Clinton's use of a private server and email address during her tenure as secretary of state.
House Republicans were already in action Thursday, grilling FBI Director James Comey for hours about his agency's handling of the case.
Comey told the House Oversight and Government Reform Committee that his investigation found evidence of "great carelessness" by Hillary Clinton's handling of classified information but no evidence that she or her staff illegally discussed classified information.
"They were not careless and the material that they sent, they did not believe that was classified."
"That's intent", Chaffetz replied.
"And so an unauthorized server in the basement is not mishandling?"
When asked if he stood by the FBI's decision to seek felony charges against Petraeus, Comey responded "Oh, yeah".
He then asked if there was any classified material on the servers.
Just three were marked confidential - using what is known as a portion marker - in the email's text, but none had the proper headers that should have been used to indicate classification. Here are 22 times Clinton swore to voters that she didn't.
"I assume they will pay very close attention" to the Justice Department's findings, she said.
"We did not develop clear evidence of that", he said.
"House Republicans are doing what they always do, using taxpayers' money to investigate claims that have already been debunked", Cummings said.
Comey's rebuke of Clinton fanned the controversy and could still complicate her increasingly tight race against Republican rival Donald Trump.
"We have no basis to conclude she lied to the FBI", Comey said.
"Did she lie to the public?"
"Before this investigation, I would have said yes", Comey replied.
But committee Chairman Jason Chaffetz would not relent, following up with a question if the Clinton Foundation was "tied into" the email investigation.
"Not to my knowledge". "But we do not investigate crimes in Congress".
An additional 2,000 emails contained information that was later upgraded to classified after the fact.
In another interview to MSNBC, Clinton said there was no evidence of hacking of the server which hosted her emails.
The position is a striking rebuttal to Comey, who twice this week called her behavior "extremely careless", even while asserting it did not violate the law.
Although, the Department of Justice has the right to decide whether to charge Mrs. Clinton regarding the email anomaly, Ms. Loretta Lynch said earlier she would still follow suit as per instructions of the Federal Bureau of Investigation and the Prosecutor's directive.
"There was a lot of great questioning, but I was once again particularly impressed by my colleague from South Carolina, Trey Gowdy", he posted on Facebook along with a video of Gowdy interrogating Comey, encouraging his Facebook followers to watch it.
"That would be celebrity hunting", Comey said.