This image provided by the Roane County Jail shows Shirley Ann Gray. Gray and her husband, Michael Anthony Gray, face charges after police found the skeletal remains of a girl buried in their yard. The Roane County, Tenn., couple, arrested on Monday, May 25, 2020, are charged with aggravated child abuse, especially aggravated kidnapping, aggravated child neglect and abuse of a corpse, authorities said. (Roane County Jail via AP)

KNOXVILLE, Tenn. - The remains of a second child that belonged to a Tennessee couple facing abuse charges have been found buried in a yard, court records said.

A search warrant affidavit says police recovered the remains of a boy from a Knox County property where Michael and Shirley Gray lived until about 2016, news outlets reported on Friday.

Police began searching the property after finding the body of a girl buried under a barn at the Gray's current home in nearby Roane County.

The Grays had three children in their custody when they were arrested Monday on charges of aggravated child abuse, especially aggravated kidnapping, aggravated child neglect and abuse of a corpse, authorities said.

According to the search warrant, police think the remains found in Knox County belong to the couple’s adopted son, Jonathan Gray, who likely died in 2015 or 2016.

The Grays did not report either death and kept receiving financial benefits for both children, the warrants state.

Police began investigating the Grays after someone noticed a little boy walking along a Roane County road and called 911. A responding officer began asking questions and the boy's legal guardian soon confessed, arrest warrants said, to burying the remains of a little girl in a barn and locking a 15-year-old boy in the basement for four years.

The two other children spent time in a wire dog cage, while all were supposedly homeschooled and appeared to be “stunted in growth,” the arrest warrants said.

The surviving children, ages 11 to 15, were removed from their custody by the state Department of Children’s Services.

The oldest had been locked in the partially flooded, unfinished basement for stealing food shortly after the family moved to the home in June 2016, authorities said, "and had no contact with anyone outside the basement, only given small amounts of food, being white bread and some water,” the warrants state.

Michael Gray told authorities that the girl was about 10 when she died in 2017, a few months after she too was locked in the basement, and that he buried her inside a barn in the backyard, the warrants said.

The Grays remained in custody on Friday. Online jail records don't say if they have an attorney.

News from © The Associated Press, 2020