Secretary of State Hillary Clinton used her personal email account to handle high level negotiations in 2011 for a no-fly zone to help topple Libyan dictator Muammar Qaddafi, according to a series of emails obtained by Fox News, challenging her claim the private server did not hold classified information.

The emails, linked here, conflict with Clinton's statement that she did not put national security at risk by using a personal account.

"I did not email any classified material to anyone on my email. There is no classified material,"  Clinton, now a candidate for president, told reporters in March. "I'm certainly well-aware of the classification requirements and did not send classified material."

That claim was hard to test because emails released by the State Department are heavily blacked out. But an email chain from March 23, 2011 -- with virtually no redactions -- shows a message for senior administration staff including then Deputy National Security Adviser Denis McDonough, then-Under Secretary of State for Political Affairs William Burns, Under Secretary of Defense for Policy, Michele Flournoy among others.  It goes point by point, explaining what Turkey, France and Britain will likely accept in the deal.

"I think the information in the email is clearly classified. If I were engaged in the negotiation on that subject reporting back to Washington, my reporting cable would be classified,"  former UN Ambassador and Fox News contributor John Bolton said after reading the un-redacted emails.

"They're dealing with the possible U.S. military operation, sensitive negotiations among NATO partners, talking about U.S. objectives and political arrangements and possible objections to the deal from key partners so all of these at secretary of state level is extraordinarily sensitive."

The email chain also contains exchanges with Clinton aide Jake Sullivan who writes "I will forward you (Clinton) the Turkish proposal momentarily."  Clinton responds "I'm worried that FR (France) and/or the UK know about the Turks idea and want to derail it."

As the negotiations for a no-fly zone continue, Sullivan notifies Clinton that then-deputy chief of mission Christopher Stevens, who was later killed in the 2012 Benghazi attack, was moving into eastern Libya.

"At that time of course, the country was in chaos, so the situation was very dangerous. His mission was quite sensitive to link up to the opposition,"  Bolton said.  "And just having that information floating around …would obviously expose Stevens and others to great peril."

While the first email in the chain is marked "UNCLASSIFIED," based on his experience as ambassador to the UN, Bolton said he suspects a lot of intelligence was pushed out as unclassified to accommodate her separate, private system.

"It's not simply the effect on Secretary Clinton's own email. It's pervasive throughout the higher levels of the department, which simply magnifies the risk." Bolton added.

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.