WASHINGTON (REUTERS) - Dominion Voting Systems on Monday (Feb 22) filed a defamation lawsuit against businessman Mike Lindell, chief executive of My Pillow, for spreading false conspiracy theories that Dominion's machines rigged November's presidential election.

The Denver-based company filed the case in federal court in Washington, seeking US$1.3 billion (S$1.7 billion) in damages. Chaska, Minnesota-based My Pillow is named as a co-defendant in the lawsuit.

Dominion previously filed similar lawsuits against Mr Rudy Giuliani and Mr Sidney Powell, two lawyers who promoted former US president Donald Trump's baseless claims of widespread election fraud.

"Acting in concert with allies and media outlets that were determined to curry favor with one of their biggest sponsors and to promote a false preconceived narrative about the 2020 election, Lindell launched a defamatory marketing campaign about Dominion that reached millions of people and caused enormous harm to Dominion," Dominion's lawyers said in the lawsuit.

A My Pillow representative did not immediately respond to an e-mail seeking comment on the lawsuit.

Mr Lindell, a devout supporter of Mr Trump, financed post-election protest movements in a bid to overturn President Joe Biden's victory.

Mr Lindell used his personal Twitter account, which had nearly half a million followers before being suspended, and the company's account to spread unsubstantiated claims of widespread voter fraud in the presidential election.

The founder and chief executive officer of the My Pillow company, Mr Lindell's political commentary and advertisements are a regular fixture on conservative media.

A self-described former cocaine addict and alcoholic who says he found sobriety through Christianity, Mr Lindell helped sponsor a two-week March for Trump bus tour that ended in Washington on Dec 14 and spoke at five stops.