WASHINGTON, Oct 17 (Reuters) - Undersecretary of State Patrick Kennedy pressured the FBI to unclassify certain emails from Hillary Clinton's private server that were previously deemed classified, according to FBI documents released Monday that cited redacted sources.

In the documents, an unnamed person interviewed by the FBI said Kennedy contacted the FBI to ask for the change in classification in "exchange for a 'quid pro quo.'"

Whether or not Clinton sent classified emails from her private server that could have jeopardized national security has become a key issue ahead of the U.S. presidential election on Nov. 8, when Clinton will face Republican nominee Donald Trump.

(Reporting by Julia Edwards, Editing by Franklin Paul)

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