MEEKER, Okla. - Four people face charges after a severely malnourished Oklahoma teenager was found living in a barn with farm animals, subsisting on sticks, leaves and grass, according to officials.

Lincoln County First Assistant District Attorney Adam Panter told the Shawnee News-Star that the boy's father, stepmother and two older brothers have been arrested on complaints of child neglect.

The 15-year-old boy was found at a home near Meeker July 12 after a concerned passerby noticed something wasn't right.

Investigators say the teen was close to death – he weighed just 80 pounds and was not being fed. Instead, he was forced to eat twigs and grass, even though the family's home was fully stocked with food.

The boy was living inside a barn alongside farm animals including goats, rabbits and chickens, according to The Oklahoman.

An affidavit says that he would have likely been dead within a week.

"We're incredibly thankful that someone called...they literally saved this child's life," Panter told the newspaper. "He could have died and been buried on that property and no one would have ever known."

In addition to being malnourished, the teen also had several broken bones and shotgun pellets still in his legs.

The boy had a wound to the top of his head that investigators said contained maggots. Prosecutors believe the boy's father, 34-year-old Jimmy Jones Sr., dug out some of the maggots and tried to close the cut using glue, the affidavit says.

Panter told the paper that the boy's father has a full-time job as a prison guard. Jones Sr. has been jailed on an additional charge of child abuse by injury.

Police also arrested the boy's stepmother, 46-year-old Amy Jones and two brothers, 20-year-old Johnathan Plank and 24-year-old Tyler Adkins.

The brothers are being held at the Pottawatomie County Public Safety Center, while the parents are in Lincoln County Jail.

The boy was taken to a local hospital for treatment.