The inspector general for the intelligence community has contacted the Justice Department about the presence of emails in former Secretary of State Hillary Clinton's private account that contained classified information.
A spokeswoman for I. Charles McCullough, III, the intelligence community IG, said he sent a referral to the FBI earlier this month.
"The letter IC IG sent to FBI earlier this month was a counterintelligence referral indicating there is a compromise of classified national security information in former Sec. Clinton's emails. The emails exist on a at least one private server and thumb drive and that was the counterintelligence information concern we referred to the FBI," said spokesman Andrea Williams in an email.
A Justice Department official said Friday that "The Department has received a referral related to the potential compromise of classified information. It is not a criminal referral." Earlier in the day, Justice referred to it as a "criminal referral" before revising the statement.
The spokeswoman for McCullough noted that "We don't make criminal referrals "“ that is over to FBI to decide how to proceed." And late Friday afternoon, McCullough's office and the State Department IG issued a joint statement that further explains the action, calling it a "security referral for counterintelligence purposes."
The Justice Department does not appear to have made a decision about whether to launch an inquiry.
The New York Times first reported the referral late Thursday night.
The revelation is certain to intensify interest in Clinton's unusual private server arrangement during her time as secretary of State as the 2016 elections draw closer.
At the outset of a speech on the economy Friday afternoon, Clinton made brief comments about the revelation and the Times' story, which her campaign has pushed back against and has been modified since first publishing. "There have been a lot of inaccuracies," she said. "Maybe the heat is getting to everybody — we all have a responsibility to get this right. I have released 55,000 pages of emails. I have said repeatedly that I will answer questions before the House committee.
"We are all accountable to the American people to get the facts right and I will do my part. But I'm also going to stay focused on the issues, particularly the big issues that matter to American families."
Nick Merrill, a spokesman for Clinton's presidential campaign, said in a statement that Clinton "followed appropriate practices in dealing with classified materials."
"As has been reported on multiple occasions, any released emails deemed classified by the administration have been done so after the fact, and not at the time they were transmitted," he said.
The referral stems from a review by the inspectors general for the Intelligence Community and the Department of State's handling of emails. Several memos from the internal watchdogs made public Friday identified problems with State's management, under public records law, of emails containing classified information.
On Friday McCullough's office released a memo that was provided on Thursday to the leaders of the congressional intelligence committees about the status of the review of State's protocols. It notes that State has discovered that there are "potentially hundreds" of emails in the 55,000 pages worth that Clinton turned over to her former agency that may contain classified information.
The memo also reveals that a limited review conducted by McCullough's office of 40 emails revealed four that contained classified intelligence community information "which should have been marked and handled at the SECRET level." Those emails have not been released by the State Department, according to the memo from the intelligence community and State Department inspectors general.
Andrea Williams, the spokesman for the Intelligence Community IG, said the four emails with classified information turned up in the IG's limited review "were classified when they were sent and are classified now."
The joint statement from the IGs on the review of Clinton's emails notes that while these four messages contained "classified IC-derived information," they did not contain "classification markings" or "dissemination controls." The statement says the information "should never have been transmitted via an unclassified personal system."
The memo from McCullough to the lawmakers also notes that the roughly 30,000 emails Clinton turned over to the State Department late last year are "purported" to have been copied to a thumb drive in the possession of Clinton attorney David Kendall. McCullough notes that because his office's limited sampling turned up four emails with classified intelligence community information, he decided to refer the matter to the FBI as well as other counterintelligence officials.
The joint memo he issued with State's IG expands on the reason for the referral, stating:"The main purpose of the referral was to notify security officials that classified information may exist on at least one private server and thumb drive that are not in the government's possession." The intelligence community IG is required under law to refer potential compromises of national security information to the "appropriate" intelligence community security officials.
The McCullough memo also exposes a disagreement between State and the intelligence community IG about the portion of Clinton's emails already made public.
"My office discovered that an inadvertent release of classified national security information had already occurred in the State FOIA process as a result of insufficient coordination with Intelligence Community (IC) elements. (State personnel continue to deny the classified character of the released information despite a definitive determination from the IC Interagency FOIA process)," it states.
According to the Intelligence Community IG's spokeswoman, there has been at least one email released that contained classified national security information.
The memo provides a summary of the recommendations for preventing inadvertent release of classified information.
Rep. Trey Gowdy, the GOP leader of the House Select Committee on Benghazi, on Friday renewed his call for Clinton's private email server to be turned over to a third party for review.
"Regardless of whether the server is voluntarily relinquished or acquired by other lawful means, there is clearly sufficient cause to examine the contents of said server for the presence of other classified information. Moreover, whether it was classified initially or later classified, it is appropriate for the Executive Branch and intelligence community to determine where these now classified documents are housed and by whom they are possessed," he said in a statement.
Following conflicting accounts of the scope of a potential Justice Dept. inquiry, Elijah Cummings, the top Democrat on the House committee probing the 2012 Benghazi attacks, said in a statement Friday that State's IG told him the referral was not about "Clinton's email usage."
"Instead, he told me the Intelligence Community IG notified the Justice Department and Congress that they identified classified information in a few emails that were part of the FOIA review, and that none of those emails had been previously marked as classified," Cummings said.
"The Benghazi Select Committee has obtained zero evidence that any emails to or from Secretary Clinton were marked as classified at the time they were transmitted, although some have been retroactively classified since then," he said.
The State Department has released several thousand pages worth of Clinton's messages from her time as secretary of State, and more releases from the 55,000 pages she provided are expected monthly until early next year.
A State Department official defended the vetting process.
"Ž"We are working with both the State IG and the Intelligence Community's Inspector General to ensure that our review of former Secretary Clinton's emails is completed in a manner that protects sensitive and potentially classified information," the official said.
"To provide for greater cooperation through this process -- at the invitation of the Department --IC FOIA reviewers are reviewing emails and identifying those emails that might contain IC equities," the official added.
Emily Schultheis contributed to this article