The FBI is investigating whether members of Hillary Clinton’s inner circle “cut and pasted” material from the government’s classified network so that it could be sent to her private email address, former State Department security officials say.

Clinton and her top aides had access to a Pentagon-run classified network that goes up to the Secret level, as well as a separate system used for Top Secret communications.

The two systems — the Secret Internet Protocol Router Network (SIPRNet) and the Joint Worldwide Intelligence Communications System (JWICS) — are not connected to the unclassified system, known as the Non-Classified Internet Protocol Router Network (NIPRNet). You cannot email from one system to the other, though you can use NIPRNet to send ­emails outside the government.

Somehow, highly classified information from SIPRNet, as well as even the super-secure JWICS, jumped from those closed systems to the open system and turned up in at least 1,340 of Clinton’s home emails — including several the CIA earlier this month flagged as containing ultra-secret Sensitive Compartmented Information and Special Access Programs, a subset of SCI.

SAP includes “dark projects,” such as drone operations, while SCI protects intelligence sources and methods.

Fox News reported Friday that at least one of Clinton’s emails included sensitive information on spies.

“It takes a very conscious effort to move a classified email or cable from the classified systems over to the unsecured open system and then send it to Hillary Clinton’s personal email account,” said Raymond Fournier, a veteran Diplomatic Security Service special agent. “That’s no less than a two-conscious-step process.”

He says it’s clear from some of the classified emails made public that someone on Clinton’s staff essentially “cut and pasted” content from classified cables into the messages sent to her. The classified markings are gone, but the content is classified at the highest levels — and so sensitive in nature that “it would have been obvious to Clinton.” Most likely the information was, in turn, emailed to her via NIPRNet.

To work around the closed, classified systems, which are accessible only by secure desktop workstations whose hard drives must be removed and stored overnight in a safe, Clinton’s staff would have simply retyped classified information from the systems into the non-classified system or taken a screen shot of the classified document, Fournier said. “Either way, it’s totally illegal.”

FBI agents are zeroing in on three of Clinton’s top department aides. Most of the Clinton emails deemed classified by intelligence agency reviewers were sent to her by her chief of staff Cheryl Mills or deputy chiefs Huma Abedin and Jake Sullivan.

‘It takes a very conscious effort to move a classified email or cable from the classified systems over to the unsecured open system and then send it to Hillary Clinton’s personal email account.’ - Raymond Fournier, veteran Diplomatic Security Service special agent

In one email, Clinton pressured Sullivan to declassify cabled remarks by a foreign leader.

“Just email it,” Clinton snapped, to which Sullivan replied: “Trust me, I share your exasperation. But until ops converts it to the unclassified email system, there is no physical way for me to email it.”

In another recently released email, Clinton instructed Sullivan to convert a classified document into an unclassified email attachment by scanning it into an unsecured computer and sending it to her without any classified markings. “Turn into nonpaper w no identifying heading and send nonsecure,” she ordered.

Top Secret/SCI emails received by Clinton include a 2012 staff ­email sent to the then-secretary containing investigative data about Benghazi terrorist suspects wanted by the FBI and sourcing a regional security officer. They also include a 2011 message from Clinton’s top aides that contains military intelligence from United States Africa Command gleaned from satellite images of troop movements in Libya, along with the travel and protection plans for Ambassador Christopher Stevens, who was later killed in a terrorist attack in Benghazi.

“Receiving Top Secret SAP intelligence outside secure channels is a mortal sin,” said Chris Farrell, director of investigations for Judicial Watch, the Washington-based public law firm that has successfully sued State for Clinton’s emails.

“A regular government employee would be crucified, and they are, routinely,” added Farrell, who as a former Army counterintelligence agent investigated such violations.

The prosecution of former CIA Director David Petraeus for mishandling secret intelligence centered on a classified-information nondisclosure form he signed swearing to protect such information. Clinton signed the same agreement on Jan. 22, 2009.

As a result of Clinton’s negligence, former Defense Secretary Robert Gates said in a recent interview he thinks “the odds are pretty high” that hostile foreign powers like Iran, China and Russia hacked Clinton’s homebrew email server and stole US secrets.

Paul Sperry, a visiting media fellow at the Hoover Institution, is the author of “Infiltration.”

sperry@sperryfiles.com