Four people are going on trial in Paris over an alleged scheme that fed consumers across Europe frozen foods containing cheap horse meat fraudulently labelled as pricier beef.
The defendants at the trial include two former executives of the French company Spanghero, who are accused of various fraud charges.
The executives deny intentional wrongdoing, according to French media reports.
Horse meat turned up in a dozen European countries in 2013 in frozen supermarket meals such as burgers and lasagne, as well as in school lunches and hospital meals.
Investigators say Spanghero bought horse meat then mislabelled it as beef used in prepared foods.
The EU toughened food control rules as a result.
Horse meat is not dangerous, but the scandal shocked consumers in places where such meat traditionally is not eaten.