Francis claims that Wynn threatened to kill him and have him buried in the desert in emails and conversations with record producer Quincy Jones in 2010. Francis first made the claims while embroiled in a multi-million dollar dispute over a gambling debt.
Wynn later sued for slander.
Francis repeated the claims during a trial that began Tuesday in Los Angeles. He says he took the warnings from his neighbor Jones seriously.
Wynn is the CEO of Wynn Resorts Ltd. and developed many of Las Vegas' signature hotels including The Mirage and Bellagio. He testified he has never sent an email in his life.