PETALUMA, Calif. – Federal authorities believe Rancho Feeding Corp. was buying diseased cattle and processing them out of sight of federal inspectors, CNN reported.

Rancho Feeding is under criminal investigation by the federal government for killing and selling meat from dairy cows that allegedly had eye cancer. The company allegedly bought cows with eye cancer, and employees removed the heads and trimmed diseased parts so inspectors couldn't detect the disease. Rancho Feeding recalled more than 8 million lbs. of meat, one of the largest beef recalls in years.

The federal probe also uncovered an inappropriate relationship between a federal meat inspector and a plant foreman. Federal investigators began scrutinizing Rancho Feeding following a tip from a former employee.

Marin Sun Farms, a specialty meat purveyor in Point Reyes Station, Calif., successfully acquired Rancho Feeding's slaughterhouse. Despite its problems, Rancho Feeding is crucial to the network of meat producers who fill a niche market for locally produced, specialty meats.