A federal grand jury, investigating one of the largest food-related recalls ever, indicted four executives at the now-defunct Peanut Corp. of America, accusing them of knowing that their products were tainted with salmonella bacteria, covering up the evidence and selling the food anyway.

The 76-count criminal indictment, disclosed Thursday, accused the four of engaging “in multiple schemes to defraud the company’s customers.”

Named as defendants were the former president, Stewart Parnell; his brother Michael, a food broker representing the company; Samuel Lightsey, operations manager at the company’s Blakely, Ga., plant; and Mary Wilkerson, the plant’s quality-assurance manager.

Peanut butter, roasted peanuts and other items prepared at the plant were linked to a 2009 salmonella outbreak that sickened more than 700 people in 46 states and may have contributed to nine deaths, including that of 80-year-old Clifford Tousignant.

“I didn’t think there’d ever be any criminal charges filed. It was something I had pretty much given up on,” said his son, Lou Tousignant of Walnut Creek, Calif. “I’m a little emotionally shot, but it’s a pretty good day.”

The four executives allegedly failed to keep rodents and insects out of the Blakely plant, continued to ship products even when testing showed salmonella contamination, fabricated quality-assurance labels and lied to and misled investigators once the outbreak occurred, according to the Justice Department.