CLEVELAND, Ohio (AFP) - Republican delegates savaged Democrat Hillary Clinton on Tuesday (July 19) by breaking into angry chants of "lock her up" and "guilty" as New Jersey Governor Chris Christie laid out a criminal-style case against her.

While the FBI stopped short of recommending charges against the presumptive Democratic nominee over her e-mail scandal, Mr Christie, himself a former federal prosecutor, went into attack dog mode on the second day of the Republican National Convention in Cleveland.

"Let's do something fun tonight," he said. "We are going to present the facts to you. You, tonight, sitting as a jury of her peers in this hall and in your living rooms around our nation."

He then outlined what he called "the facts" against Mrs Clinton, savaging her record as US secretary of state, holding her responsible for the chaos and violence engulfing Libya, and asking whether she is "guilty or not guilty" of being an apologist for Boko Haram in Nigeria.

"As an awful judge of the character of a dictator and butcher in the Middle East, is she guilty or not guilty?" he shouted in reference to Syrian President Bashar al-Assad.

"Guilty," came back the frenzied answer from the crowd.

"America and the world are measurably less safe because of the Iran deal Hillary helped cut. An inept negotiator of the worst nuclear arms deal in American history, guilty or not guilty?" he bellowed.

"Guilty!" said the crowd.

Mrs Clinton is being probed for using a private e-mail server to handle sensitive government documents while serving as secretary of state, something the FBI said was careless but not criminal.