The email in question, forwarded to Clinton, the presumed Democratic presidential candidate in 2016, by her deputy chief of staff Jake Sullivan, relates to reports of arrests in Libya of possible suspects in the attack in which four Americans were killed.
The information was not classified at the time the email was sent but was upgraded from "unclassified" to "secret" on Friday at the request of the FBI, according to State Department officials. They said 23 words of the Nov. 18, 2012, message were redacted from the day's release of 296 emails totalling 896 pages to protect information that could damage foreign relations.
Because the information was not classified at the time the email was sent, no laws were violated, but Friday's redaction shows that Clinton received sensitive information on her unsecured personal server.
No other redactions were made to the collection of Benghazi-related emails for classification reasons, the officials said. They added that the Justice Department had not raised classification concerns about the now-redacted 1 1/2 lines when the documents were turned over to the special House committee looking into the Benghazi attack in February. The committee retains a complete copy of the email, the officials said.
It is at the end of a chain of communication that originated with Bill Roebuck, the then-director of the Office of Maghreb Affairs, that pointed out that Libyan police had arrested several people who might have connections to the attack. The redacted portion appears to relate to who provided the information about the alleged suspects to the Libyans. A total of five lines related to the source of the information were affected, but only the 23 words were deleted because the FBI deemed them to be classified.
Roebuck's email was sent to a number of senior officials, including the former assistant secretary of state for near eastern affairs, Elizabeth Jones, who then sent it to Sullivan with the comment: "This is preliminary, but very interesting. FBI in Tripoli is fully involved."
Sullivan then forwarded the email to Clinton with the comment: "FYI."
There was no immediate indication that Clinton herself forwarded the email.