Several emails found on former Secretary of State Hillary Clinton's unsecured private email server contained information classified even higher than "top secret," the intelligence community inspector general recently told lawmakers, according to Fox News.

Inspector General I. Charles McCullough III sent a letter to senior Republican lawmakers on Jan. 14 saying that several dozen more emails containing classified information were found, including specific intelligence from a "special access program" (SAP).

"To date, I have received two sworn declarations from one [intelligence community] element. These declarations cover several dozen emails containing classified information determined by the IC element to be at the confidential, secret, and top secret/sap levels," the letter states.

Information from an SAP is more sensitive than a "top secret" classification because the intelligence could reveal sources of information, and only a handful of people at the top levels of government have access, according to Breitbart.

The FBI is currently investigating the Democratic presidential candidate's home email system to determine whether she jeopardized or mishandled classified information during her tenure as the nation's top diplomat from 2009 to 2013.

Nearly 1,400 emails found on Clinton's server have been retroactively classified, including at least two containing "top secret" information. Clinton has insisted that she never sent or received messages marked as classified, but the latest discovery of SAP level intelligence makes it more difficult for her to feign ignorance, notes Business Insider. "There is absolutely no way that one could not recognize SAP material," a former law enforcement official with extensive knowledge of SAP told Fox News. "It is the most sensitive of the sensitive."

Former CIA Director David Petraeus was prosecuted for sharing information from SAPs with his mistress and biographer Paula Broadwell, notes Fox News. The prosecution relied heavily on a non-disclosure agreement that Petraeus signed, agreeing to protect the information and acknowledging that "unauthorized disclosure, unauthorized retention or negligent handling ... could cause irreparable injury to the United States or be used to advantage by a foreign nation." Clinton signed the same agreement in January 2009.

Clinton's presidential campaign dismissed the latest findings, blaming the "same interagency dispute that has been playing out for months." The information "does not change the fact that these emails were not classified at the time they were sent or received," the campaign said, according to The Associated Press.

"It is alarming that the intelligence community IG, working with Republicans in Congress, continues to selectively leak materials in order to resurface the same allegations and try to hurt Hillary Clinton's presidential campaign," the campaign added. "The Justice Department's inquiry should be allowed to proceed without any further interference."