'Top secret' emails come back to haunt Hillary Clinton

Hillary Clinton's email saga came back to haunt her as the State Department for the first time acknowledged that "top secret" information has been found in emails sent through her private server.

The disclosure Friday would provide new fodder to the Republican opponents of the Democratic presidential front runner just three days before the first nominating contests in Iowa where rival Bernie Sanders is running neck and neck with her.

While Sanders said "there is a legal process in place which should proceed and not be politicized," several prominent Republicans, including presidential hopefuls Senators Ted Cruz and Marco Rubio, lost no time in condemning Clinton over Friday's developments.

The information was contained in 22 emails, across seven email chains, that were sent or received by Clinton through the private email server she used as Secretary of State for four years.

The emails will not be disclosed as part of an ongoing release of Clinton's email correspondence, even in highly redacted form.

State Department spokesman John Kirby said the documents, totalling 37 pages, were not marked classified at the time they were sent, but are being upgraded at the request of the intelligence community because they contain sensitive information.

A separate review by the bureaus of Diplomatic Security and Intelligence and Research is being held into whether the information in the emails was classified at the time they were sent and received, he said.

Kirby would not say when the review began or how long it would go, and acknowledged that it's possible there could be classified emails that were not marked as such.

In an interview with NBC News that was recorded before the State Department's announcement Clinton dismissed the issue as a political problem.

"There was never any information sent or received that was marked classified to me," Clinton said, adding, "I just don't see it as anything that will in any way cause any voter with an open mind to have any concerns."

Brian Fallon, a spokesman for Clinton's campaign, said in a statement that Friday's development was a case of "over-classification run amok."

Asked Friday if he had "certainty and confidence" that Clinton will not be indicted over the email controversy, White House Press Secretary Josh Earnest said any decision to prosecute Clinton would rest with the Justice Department.

"That is a decision to be made solely by independent prosecutors," Earnest said. "But again, based on what we know from the Department of Justice, it does not seem to be headed in that direction."