Dec 13 (Reuters) - Fox Corp (FOXA.O) Chairman Rupert Murdoch is set to be questioned under oath on Tuesday in a defamation lawsuit over his network’s coverage of unfounded vote-rigging claims during the 2020 U.S. presidential election.Election technology company Dominion Voting Systems is seeking $1.6 billion in damages from Fox News Network, which it alleges spread false claims that its machines were used to rig the 2020 election against Republican Donald Trump and in favor of his Democratic rival Joe Biden.The complaint cited instances where, in the aftermath of the 2020 presidential election, Trump allies like Rudy Giuliani and Sidney Powell appeared on Fox News and falsely claimed Dominion software may have manipulated vote counts in favor of Biden.And they used the machines to trash large batches of votes that should have been awarded to President Trump.”Murdoch’s high-stakes deposition on Tuesday comes as Dominion has spent the past several months questioning a parade of Fox News hosts, executives and producers.Fox hosts and co-hosts Tucker Carlson, Laura Ingraham, Jeanine Pirro and Bret Baier have also been questioned in recent months, court records show, as well as former host Lou Dobbs."