Dominion Voting Systems has sued Mike Lindell, Sidney Powell and Rudy Giuliani, MyPillow CEO. Drew Angerer/Getty Images, Tom Williams/CQ Roll Call Inc. via Getty Images. Joshua Roberts/Getty ImagesDominion summoned Rudy Giuliani and Sidney Powell to testify in its lawsuit against Fox News.Fox was sued by it in March for spreading conspiracy theories about its voting machines.Giuliani and Powell now need to submit documents regarding their involvement with Fox.Check out more stories from Insider's business page.Dominion Voting Systems, a voting-machine company, subpoenaed Sidney Powell and Rudy Giuliani to MyPillow CEO Mike Lindell as part of its $1.6 billion defamation suit against Fox News.Bloomberg reported that they now must hand over documents relating to their involvement in the news network.Dominion sued the three individuals for $1.3 billion each. They were accused of spreading the false conspiracy theory that voting machines "flipped" votes from Joe Biden to President Donald Trump during the 2020 election.Dominion sued Fox News, alleging that Fox News had promoted the conspiracy theory of election fraud to boost its ratings. Fox News denied the claim repeatedly and stated that it was proud of its coverage of the 2020 election.Dominion also subpoenaed Powell, Giuliani and Lindell as part of the lawsuit. A filing in Delaware state court showed that.Bloomberg reported that Giuliani was a former New York mayor and served as Trump's personal attorney. He was asked to turn over all documents relating to his appearances on Fox from 2016 and communications with the network pertaining to the 2020 presidential election.Giuliani was also requested to submit documents regarding his relationship with the network.Dominion also sent subpoenas for Lindell and Powell to Powell, a pro Trump attorney. Bloomberg reported that they have until July 25, according to Bloomberg, citing the filing.Insider reached out to Powell, Fox News and Lindell for comment but they did not immediately reply.Continue the storyDominion's largest lawsuit against Fox News is the most serious yetDominion brought $1.3 billion in defamation suits against Powell and Giuliani, and against Lindell, in January.Dominion included many examples of the defendants making election-fraud claims in right wing media including Fox News without any resistance from hosts in its lawsuits against Powell & Giuliani.Its largest lawsuit against Fox News, worth $1.6 billion, was filed in March.Dominion claimed that the network "sold an untrue story about election fraud to serve its commercial purposes, injuring Dominion severely."Fox News stated in March that it was proud of its coverage of the 2020 election. This is in keeping with American journalism's highest traditions. It stated that it would defend itself in court against any lawsuits.In February, Smartmatic, a voting-machine manufacturer, filed a $2.7 million lawsuit against Fox News.Insider was told by a Fox News representative in February that they had conducted several fact-check segments "prior any lawsuit chatter."Fox News, Powell, Giuliani and Lindell asked for the dismissal of the lawsuits.Business Insider has the original article.