Luverne, MN (MNN)  --  The Rock County Attorney's Office has decided not to file charges against seven workers at a Minnesota hog farm who were seen in a video apparently mistreating animals.  

hog farm/Getty Images

California-based Last Chance for Animals shot the video at Christensen Farms in Luverne.  Christensen suspended the workers and launched its own investigation.  

The county says it won't file the animal cruelty charges because the videos were edited, meaning they couldn’t be used as evidence.  An outside veterinarian reported finding nothing at the farm which could be the basis for criminal charges.  

The animal protection group says politics played a role in the decision and vows to continue to press the case.