The manager of the Peanut Corporation processing plant in Georgia confessed that he hid salmonella test results from government inspectors.
Peanuts from the plant are held responsible for sickening about 6,000 people across the United States.
The first outbreaks were reported in January, 2009, and by the time the extent of the food poisonings was known, the company was in bankruptcy before the end of the year.
During a trial that has just begun, plans manager Samuel Lightsey said he lied to Food and Drug Administration investigators about positive tests for salmonella in the company's product and about the frequency of testing done at the plant.
"I was trying to play damage control, trying to protect the company," Lightsey testified at the trial of his former boss and company owner Stewart Parnell, and two others.