A Paris court on Monday began hearing a libel case by the head of a company that supplies Taser stun guns to French police against a Trotskyist leader who said the weapons can be lethal.
The hearing began just a few days after Antoine Di Zazzo, head of SMP Technologies, was charged with spying on the man he is suing, Olivier Besancenot, leader of the Communist Revolutionary League (LCR).
SMP Technologies is seeking 50,000 euros (66,000 dollars) in damages from Besancenot because he said in a blog and a newspaper interview that Taser guns had "probably silenced more than 150 people in the US."
Ex-presidential candidate Besancenot says he was simply drawing attention to an Amnesty International report on Tasers that said that nearly 300 people have died around the world after being zapped with a Taser.
He is calling for a moratorium on the weapon's use while a full investigation is conducted into their safety.
Like Taser, Di Zazzo, whose company has supplied Tasers to the French army, police and gendarmerie since 2004, adamantly denies the guns can be lethal. Darts fired by the Taser pack a 50,000-volt punch that can paralyse targets from 10 yards (metres) away.
Di Zazzo was arrested last week, along with several people who included police officers, private detectives and a customs official, on suspicion of having spied on Besancenot and his partner and gaining access to their bank details.
Di Zazzo has admitted he hired private eyes to find Besancenot's address -- saying he wanted to ensure the politician received a court summons -- and to find out what his assets were.
But he says that his inquiries went no further than that.
Besancenot is winding up his LCR to found a New Anti-Capitalist Party, which will seek to tempt members of France's Communist Party, environmentalists, disaffected Socialists and anti-globalisation activists.