The lead prosecutor of Israeli spy Jonathan Pollard predicted on Tuesday that the FBI would recommend Espionage Act charges in its investigation of Hillary Clinton’s private email server.

"No honest FBI will ever not [recommend] criminal charges in this case," former U.S. Attorney Joseph diGenova said during an event hosted by conservative watchdog group Judicial Watch. "There are going to be referrals for a series of criminal charges involving violations of the espionage statutes, the grossly negligent mishandling of classified information, the grossly negligent storage of classified information."

Fox News reported last year that the FBI’s probe of Clinton’s private server is partially focused on potential violations of a section of the Espionage Act. The section in question prohibits individuals with security clearances from handling classified information in a way that constitutes "gross negligence."

In 1986, diGenova was the chief U.S. prosecutor in the case against Jonathan Pollard, one of the most notorious spies of the last half-century. Pollard, a former U.S. Navy intelligence analyst, pleaded guilty to an Espionage Act violation for passing top-secret information to Israel. He was sentenced to life in prison, but was paroled in 2015 after a lengthy lobbying campaign by his supporters.

DiGenova, a long-time critic of Clinton, said the FBI might recommend lower level charges, as in the Espionage Act case against former CIA director David Petraeus.

Petraeus pleaded guilty last April to a misdemeanor after he allegedly gave personal journals that contained classified information to his girlfriend and biographer. He was sentenced to two years probation and a $100,000 fine.

"[The FBI] may not recommend felonies, as a courtesy to a woman who was the first lady for eight years, a senator and the secretary of state," diGenova said. "They may as a courtesy try to do what they did with General Petraeus, and recommend misdemeanors. But make no mistake, they are going to recommend that she and others be charged with crimes."

Although confidential, secret, and top secret information was found in Clinton’s emails, the Democratic frontrunner has said this information was not classified at the time it was sent.

DiGenova said the Department of Justice’s recent decision to grant immunity to Clinton’s technology aide, Bryan Pagliano, suggested that a grand jury had been convened.

"In all likelihood, [Pagliano] got statutory immunity, which means he went before a federal judge, and you do that when you have a grand jury," diGenova said.

DiGenova was speaking at a panel hosted by the watchdog group Judicial Watch. The panel also included Judicial Watch president Tom Fitton, attorney Michael Bekesha, and Jason Leopold, the Vice News reporter whose public records lawsuit forced the State Department to release around 30,000 of Clinton’s emails on its website.