Hillary Clinton's defeat in the 2016 presidential election won't halt House Republicans' probe of her private email server, an investigation that could bring "a lot of other characters" into congressional crosshairs, according to the top GOP investigator.

"This was never a political targeting in the beginning and just because there was a political election doesn't mean it goes away," House Oversight and Government Reform Chairman Jason Chaffetz, R-Utah, told reporters Monday. "There were a lot of other characters that were involved in this that we have to look at."

Their review will encompass an array of figures, ranging from Clinton's ousted team to incumbent leaders of the FBI.

"This was potentially one of the largest breaches of security in the history of the State Department," he said. "It cannot and should never be repeated again. How is it that so much information was able to migrate out into the world? These are still open questions that we need to finish up so that they don't happen again."

Chaffetz wants to review the security clearances of Clinton aides who helped manage the "extremely careless" email process described by FBI Director James Comey. Chaffetz said he is inclined to hold Bryan Pagliano, a key Clinton IT aide, in contempt of Congress for flouting subpoenas last year. "You can't just get a subpoena from Congress to testify and not show up," he said.

The Utah Republican wants to target more senior officials, such as State Department Under Secretary for Management Patrick Kennedy, in light of FBI suggestions that he tried to set up a "quid pro quo" with the FBI to suppress revelations that Clinton's email server held classified information.

FBI leadership could also be a live target of the review, as Republicans are troubled that Va. Gov Terry McAuliffe, a longtime ally of the Clintons, made campaign donations to the wife of Andrew McCabe, the agency's second-in-command. "I'm very concerned about the straight-up conflict of interest that Mr. McCabe had," Chaffetz said. "That's something we'll continue to spend resources on."

Trump regularly led "lock her up" chants on the campaign trail, but Chaffetz hinted that the collaboration might not be as automatic as the party registration of Trump and the lawmakers might suggest. "It depends how cooperative the administration is going to be. We're going to work with [White House General Counsel Don] McGahn and [incoming] Attorney General Sessions and others to see what sort of documents and what sort of access we're going to be allowed."

Even if the White House does sign off, Chaffetz suggested that lower level State Department officials might hamper the probe. "We're still dealing with the massive bureaucracy; changing the secretary of state doesn't necessarily change the whole bureaucracy," Chaffetz said. "I don't want this to linger, but the reason we're still talking about it now is because stuff that we've been asking for since 2010 still hasn't arrived."