(Bloomberg) -- A voting-machine company falsely accused of rigging the 2020 election against Donald Trump is seeking to question two former administration officials and Georgia’s elections chief as part of its $1.6 billion defamation suit against Fox News.

Dominion Voting Systems Inc. on Wednesday subpoenaed Georgia Secretary of State Brad Raffensperger, who was pressured by Trump to flip the state’s election results after Joe Biden was declared the winner. The company is also seeking to question Christopher Krebs, the former top cybersecurity official at the Department of Homeland Security whom Trump fired for refusing to question the integrity of the election.

Dominion’s subpoena of Raffensperger comes as Atlanta prosecutors appear to be stepping up a probe into a phone call in which Trump asked the state official to “find” votes for him. Fulton County District Attorney Fani Willis’s office on Tuesday subpoenaed Rudy Giuliani, Senator Lindsey Graham and five others to testify before a special grand jury.

According to Dominion, Fox News knowingly broadcast false claims that voting machines were rigged in order to win back viewers upset that the conservative network had called the election for Biden. The voting machine maker’s suit notes that ratings for one Fox News show spiked when Giuliani and former Trump campaign lawyer Sidney Powell appeared on-air to claim that Dominion gave “kickbacks” to Raffensperger “for its contract to provide voting machines to the state.”

“The false accusation that Dominion had bribed Georgia officials—a claim for which Powell never offered a shred of evidence—was manufactured out of whole cloth in order to discredit Georgia Republicans after they publicly rebutted” the conspiracy theory, according to the complaint.

Dominion declined to comment, and Fox didn’t immediately respond to messages seeking comment. Raffensperger also didn’t immediately respond to a request for comment.

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Krebs was fired by Trump after he sent a tweet rejecting vote-rigging claims made by Powell in an appearance on Fox Business. Dominion argues that public statements by Raffensperger and Krebs, both Republicans, confirmed the veracity of Biden’s victory and put Fox on notice that the election wasn’t fraudulent, as some of its personalities and guests were claiming.

In addition to Krebs, Dominion also subpoenaed Benjamin Hoveland, a US Election Assistance Commissioner who in 2020 administered hundreds of millions of dollars in grant money to election officials to help respond to the pandemic, court records show.

Neither Krebs nor Hoveland immediately responded to requests for comment.

A judge in December ruled Dominion’s suit against Fox News could go forward because the network probably had enough information after the election to know the conspiracy theory was false. The judge last month also allowed Dominion’s claim against Fox’s parent company Fox Corp. to move forward, because Rupert and Lachlan Murdoch may have acted with “actual malice” in directing the network to broadcast the conspiracy.

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