Human remains found at a Kansas barn have been confirmed to be those of a juvenile, but determining whether they belong to a missing 7-year-old boy could take weeks, a coroner said Tuesday.

Police found the remains after investigating a domestic disturbance, during which they were notified that the boy had disappeared. The boy’s father, Michael A. Jones, was charged Monday with child abuse, aggravated battery and aggravated assault with a firearm and is being held on $10 million bond.

Jones has not been charged in connection with the disappearance of the child, who is referred to in court records as A.J., or with the discovery of the remains.

Jeff Coon, Jones' father-in-law, told The Kansas City Star Tuesday that his daughter called him on Thanksgiving Day and said that her husband had killed the boy and fed his body to pigs. Heather Jones had been married to Michael Jones for about seven years and is not the mother of the missing child.

"She told me that Mike killed the little boy and it would be all over the news," Coon told The Star. "He fed him to the pigs, is all she said."

Wyandotte County District Attorney Jerome A. Gorman declined to address that report but has said investigators described the scene "as one of the worst things that they have ever seen."

Wyandotte County Coroner Dr. Alan Hancock said the remains have been sent to a forensic anthropologist to confirm the child's approximate age and race. Hancock said the process could take several weeks.

Jerome Jones, Michael A. Jones’ father, told the Associated Press his son would never hurt a child. Jones is being held in the Wyandotte County Detention Center and it’s unclear whether he has a lawyer.

"Mike is not the type of person that would do ... what's he's accused of doing," Jerome Jones said.

The abuse and battery charges are related to an alleged attack on Heather Jones. Gorman said Monday that the discovery of human remains launched a "much larger investigation."

He said the child abuse charge, described as "torturing or cruelly beating," indicates the boy was abused between May 1 and Sept. 28. That charge is "the tip of the iceberg" in the case involving the boy, Gorman said.

Coon told The Star that his conversation with Heather Jones on Thanksgiving was the first time he had talked to his daughter in six months and that he hadn't been to her home in two years.

Six girls ranging in age from 10 to younger than 2 were taken from the Jones home and are in state custody. They are healthy and safe and will be under court jurisdiction "for some time," Gorman said. Investigators are trying to determine the parents of each child.

Coon said four of the girls are the biological children of Heather and Michael Jones. The two other girls, as well as A.J., are believed to be Michael Jones' children from previous relationships.

The children were home-schooled. Ann Bush, spokeswoman for the Kansas Department of Education, said Michael Jones and his wife registered to home-school their children on July 17, 2012. The official name they used was the Jones Academy.

After the registration via an online form, the state has no other connection to the school. Bush said home-schoolers do not have to meet any other state requirements.

Jones’ next court appearance is scheduled for Dec. 8.

The Associated Press contributed to this report.