Raleigh, N.C. — The top prosecutor in Sampson, Duplin and Onslow counties said Monday that there is insufficient evidence of animal abuse by workers at farms linked to Butterball LLC to pursue criminal charges.

Mercy for Animals conducted an undercover investigation in October and collected hidden-camera video of what the the animal-rights group described as turkeys being kicked, stomped on, dragged by their wings or necks and thrown into crates on top of other birds.

The footage was shot at turkey farms in Cumberland, Sampson, Duplin, Lenoir and Onslow counties, although the group said there was little evidence of abuse at the Cumberland County farm.

Ernie Lee, the district attorney for Sampson, Duplin and Onslow counties, said he reviewed the video with several assistant prosecutors and studied state and federal regulations for handling poultry before deciding not to press criminal charges in the case.

"After reviewing the video footage and documentary material, I do not believe that we can prove beyond a reasonable doubt that acts of animal cruelty were committed by the employees depicted in the video based upon applicable North Carolina law," Lee said in a statement.

He said the video shows workers trying to move the turkeys to a truck, and they don't even touch most of the birds.

"Any contact with the turkeys did not appear to be egregious or malicious in nature and did not appear for the purpose of tormenting the turkeys," he said.

Nathan Runkle, executive director of Mercy for Animals, said he found it "extremely troubling" that Lee won't prosecute the case, saying the video clearly shows criminal wrongdoing.

"This case graphically illustrates the need for stronger animal protection laws in North Carolina and greater federal protection from animal abuse. Turkeys, and all animals, deserve to be treated humanely during their lives, even if they are ultimately slaughtered for food," Runkle said in a statement.

The group said it is considering filing suit against Butterball and called for a consumer boycott of the Garner-based company's products.

Butterball suspended the workers shown in the videos while it conducted an internal investigation. The company maintains that it has a zero-tolerance policy regarding animal abuse.

Mercy for Animals last year conducted another undercover investigation at a Hoke County turkey farm. Authorities subsequently raided the farm and arrested five workers.

At least one worker pleaded guilty in the case. Also, the top poultry veterinarian at the state Department of Agriculture & Consumer Services pleaded guilty to tipping off the farm to the raid.