The State Department is denying a top official offered to make a deal with the FBI over classifying an email on former Secretary of State Hillary Clinton's private server.

FOX's Rachel Sutherland reports from Washington:

An FBI employee interviewed during the investigation into Clinton's private server claimed Under Secretary for Management Patrick Kennedy offered to give the FBI additional slots overseas in exchange for changing classification.

Donald Trump called that quid pro quo and felony, corruption:

(Trump) "I think it's crazy what's going on. It's totally illegal. It's a criminal act, it's a crime."

State Department spokesman John Kirby says the employee's story is not true:

(Kirby) "I can't speak to what the individual remembers or how they remember it. What I can you is, we've looked into this, there was no quid pro quo, even suggested."

Trump is calling on Kennedy, who's been with the State Department for more than 40 years, to be fired.

In Washington, Rachel Sutherland, FOX News.

Follow Rachel Sutherland on Twitter: @SutherlandFOX